Blood Markers: Complete Reference for Bodybuilders

Enzyme primarily found in the liver. Elevated levels indicate liver cell damage.

PED: Oral AAS (especially 17-alpha alkylated compounds like Dianabol, Anadrol, Winstrol) significantly elevate ALT. Intense weight training can also cause mild elevation. Values 2-3x upper limit common on orals. Values up to ~100 U/L on oral AAS are common but should not be ignored long-term.

Enzyme found in liver, heart, and muscles. Elevated by liver damage or muscle breakdown.

PED: Both liver stress and heavy training elevate AST. Post-workout AST can be 2-3x normal. When AST is elevated but ALT is normal, it often indicates muscle damage rather than liver issues. Oral AAS will elevate both. Key diagnostic tip: if AST is high but ALT and GGT are normal, it is almost certainly muscle damage from training -- not liver stress.

Enzyme involved in bile duct function. Sensitive marker for liver/bile duct issues and alcohol use.

PED: Can be elevated by oral AAS. More specific to liver than AST/ALT since it's not affected by muscle damage. Good confirmatory test for liver stress vs training-induced elevation. If GGT is elevated alongside ALT/AST, liver stress is confirmed. If GGT is normal but AST/ALT are elevated, the elevation is likely from muscle damage, not liver.

Enzyme found in liver, bones, and other tissues. Elevated in liver or bone disorders.

PED: Less commonly affected by AAS than ALT/AST. Can be mildly elevated with bone-loading exercise. If elevated with normal GGT, likely bone origin rather than liver.

Waste product from red blood cell breakdown. Elevated in liver disease or Gilbert's syndrome.

PED: Usually not significantly affected by AAS alone. Elevation alongside elevated liver enzymes suggests more serious liver stress. Gilbert's syndrome (benign) is common and causes chronically mild elevation.

Protein made by the liver. Low levels indicate liver dysfunction or malnutrition.

PED: Generally stable in AAS users unless significant liver compromise. High protein diets can support albumin levels. Dehydration can falsely elevate.

Total amount of protein in the blood including albumin and globulins.

PED: High protein diets and training can push toward upper range. Dehydration can artificially elevate. Not a major concern marker for AAS users.

Group of proteins made by the liver and immune system. Includes immunoglobulins.

PED: Generally not significantly affected by AAS. Elevated globulin can indicate chronic inflammation or infection. Calculated as Total Protein minus Albumin.

Enzyme found in most tissues. Elevated levels indicate tissue damage in the heart, liver, kidneys, muscles, or red blood cells.

PED: Commonly elevated in bodybuilders due to intense training (skeletal muscle damage), haemolysis from heavy exercise, and hepatic stress from oral 17-alpha-alkylated AAS. Not specific to any single organ — must interpret alongside organ-specific markers (ALT/AST for liver, CK for muscle, haptoglobin for haemolysis). Post-workout LDH can remain elevated for 24-72 hours.

Calculated ratio of serum albumin to globulin. Reflects the balance between hepatic synthetic function and immune/inflammatory protein production.

PED: Oral 17-alpha-alkylated AAS can increase hepatic albumin synthesis, potentially raising the ratio. If hepatotoxicity progresses, albumin drops and the ratio falls. Intense training stimulates albumin synthesis during recovery. High-protein diets support albumin production. Chronic inflammation from overtraining or joint injuries elevates globulins, lowering the ratio. Dehydration concentrates all proteins but can disproportionately affect the ratio. Interpret alongside albumin, globulin, total protein, and liver function markers.

The conjugated fraction of bilirubin produced when the liver attaches glucuronic acid to free bilirubin, making it water-soluble for excretion into bile. Elevated levels specifically reflect impaired hepatic conjugation or biliary obstruction, distinguishing hepatocellular damage from haemolytic causes.

PED: Oral 17-alpha-alkylated anabolic steroids (Dianabol, Anadrol, Winstrol, Anavar) cause intrahepatic cholestasis by interfering with hepatic bile acid transport proteins, which can selectively elevate direct bilirubin even before total bilirubin rises substantially. Injectable-only cycles have minimal impact on direct bilirubin unless haematocrit is severely elevated. Rising direct bilirubin alongside elevated ALT/AST is a warning signal to reduce or cease hepatotoxic compounds immediately.

The unconjugated fraction of bilirubin produced from haem breakdown in the spleen and reticuloendothelial system. Elevated indirect bilirubin indicates either excessive production (haemolysis, ineffective erythropoiesis) or impaired hepatic uptake and conjugation. It travels bound to albumin in the bloodstream and is fat-soluble.

PED: Polycythaemia from AAS and EPO use increases red blood cell mass and therefore accelerates RBC turnover, raising indirect bilirubin. This is a benign and expected finding when haematocrit is above 50-52%. Gilbert's syndrome (affecting 5-10% of the population) independently elevates indirect bilirubin due to reduced UGT1A1 enzyme activity, and is frequently identified in athletes who have never used PEDs. Distinguishing AAS-related haemolysis from Gilbert's syndrome requires checking total bilirubin fractions alongside a complete blood count and haematocrit.

Calculated fibrosis index combining AST and platelet count. Used as a non-invasive screen for significant liver fibrosis and cirrhosis without a biopsy.

PED: Heavily confounded in lifters. AST is released from skeletal muscle after heavy or eccentric training, so APRI is inflated by exercise alone with a completely normal liver. Interpret only alongside GGT (which does not rise from muscle damage) and ideally recalculate from an AST drawn after 5-7 days of no training. Genuine elevation matters most in users of oral 17-alpha-alkylated compounds, where cholestatic injury and, rarely, peliosis hepatis or hepatic adenoma are the concern. Chronic AAS use also lowers platelets in some users, which raises APRI from the denominator side.

Waste product from muscle metabolism. Elevated levels may indicate reduced kidney function.

PED: CRITICAL: Creatinine is directly proportional to muscle mass. Heavily muscled athletes will consistently show 'elevated' creatinine that is perfectly normal for their body composition. Creatine supplementation also elevates creatinine. Standard reference ranges are inappropriate for muscular individuals. Values up to 130 umol/L are common and normal. If creatinine is elevated, confirm kidney function with a Cystatin C test -- Cystatin C is not affected by muscle mass and gives a more accurate kidney assessment.

Calculated estimate of kidney filtration rate. Below 60 suggests kidney disease.

PED: Calculated from creatinine, so muscular athletes will show falsely low eGFR. An eGFR of 60-80 in a muscular individual is likely normal. Cystatin C-based eGFR is more accurate for athletes -- request this test to get a true picture of kidney function. If creatinine-based eGFR is low but Cystatin C is normal, kidney function is fine.

Waste product from protein metabolism. Elevated with high protein intake or kidney issues.

PED: High protein diets (common in bodybuilding) will elevate urea. This is expected and not concerning unless accompanied by elevated creatinine and low eGFR. Dehydration also elevates urea.

Product of purine metabolism. High levels can cause gout and kidney stones.

PED: High protein diets can elevate uric acid. AAS can affect uric acid levels. Adequate hydration important for clearance.

Small protein filtered by the kidneys. Unlike creatinine, Cystatin C is not affected by muscle mass, making it a more accurate kidney function marker for muscular individuals.

PED: CRITICAL: The gold-standard kidney marker for athletes with high muscle mass. Creatinine-based eGFR is unreliable in muscular individuals because creatinine scales with muscle mass, giving falsely 'elevated' readings and falsely low eGFR. Cystatin C-based eGFR removes this confounder entirely. If creatinine is elevated but Cystatin C is normal, kidney function is fine — the creatinine elevation is from muscle mass. Request this test whenever creatinine or eGFR results are ambiguous. Especially important when using nephrotoxic compounds (Trenbolone, high-dose orals) or chronic NSAID use.

Estimated glomerular filtration rate calculated from cystatin C using the CKD-EPI 2012 equation. Unlike creatinine-based eGFR, this calculation is not confounded by skeletal muscle mass, dietary protein, or creatine supplementation, making it the gold-standard kidney filtration marker for muscular athletes.

PED: The most accurate eGFR for AAS users, bodybuilders, and creatine supplementers. Creatinine-based eGFR systematically underestimates true GFR in muscular individuals because muscle mass elevates serum creatinine independent of kidney function. Cystatin C-derived eGFR removes that confounder. Inoue et al. (PMID 30630856) and others have shown the cystatin C-based estimate is closer to measured GFR (mGFR by iohexol or inulin clearance) than the creatinine-based estimate in athletes. When creatinine-eGFR is borderline (50-70 mL/min/1.73m2) but cystatin C-eGFR is normal (>=90), kidney function is genuinely fine. When both are reduced, kidney function is genuinely impaired. The 2021 CKD-EPI combined creatinine plus cystatin C equation (eGFRcr-cys) is the most accurate of all, and clinical guidelines now recommend it for staging CKD when the creatinine-only estimate is ambiguous.

Albumin in urine. Elevated levels (microalbuminuria) indicate early kidney damage, even before eGFR declines.

PED: Intense training can cause transient proteinuria — collect sample on a rest day for accurate baseline. High-dose AAS, especially trenbolone and oral 17-alpha alkylated compounds, may stress kidney filtration. Elevated urine albumin alongside high creatinine or low eGFR warrants further investigation. NSAIDs (commonly used for joint pain) can also impair renal function.

Creatinine concentration in urine. Used to calculate the albumin/creatinine ratio and assess specimen adequacy.

PED: Urine creatinine is higher in muscular individuals due to greater creatinine production from muscle mass. This is expected and not a concern — unlike serum creatinine, higher urine creatinine reflects normal excretion. A very low urine creatinine may indicate a dilute specimen (over-hydration before collection).

White blood cells (leukocytes) seen on urine microscopy or detected by leukocyte esterase on dipstick. Raised counts (pyuria) usually indicate urinary tract infection or inflammation. Normally low; a typical reference is fewer than 5 cells per high-power field.

PED: Pyuria most often means a urinary tract infection, which is not PED-specific, but a few athlete-relevant points matter. Intense training, dehydration, and recent strenuous exercise can transiently raise urinary white cells, so collect a clean-catch sample on a rest day with normal hydration. Sterile pyuria (white cells with a negative culture) can follow heavy exercise or accompany interstitial nephritis from chronic NSAID use, which is common in athletes self-medicating joint pain. Always interpret alongside leukocyte esterase, nitrites, and red cells.

Red blood cells seen on urine microscopy. Their presence (haematuria) can signal kidney, ureteric, or bladder pathology, stones, infection, or trauma. Normally low; a common threshold for microscopic haematuria is 3 or more red cells per high-power field on a properly collected sample.

PED: Athlete-relevant causes are important. Intense or prolonged training, especially running and contact sport, commonly causes transient exercise-induced haematuria that resolves within 24-72 hours of rest. High-dose AAS, oral 17-alpha alkylated compounds, and trenbolone can stress renal filtration, and high muscle mass with heavy lifting raises rhabdomyolysis risk. CRITICAL distinction: a positive dipstick for blood with FEW or NO red cells on microscopy points to myoglobin (rhabdomyolysis) or free haemoglobin, not true haematuria: cross-reference creatine kinase and the Urine Blood (Hb) dipstick. NSAID use and dehydration during contest prep further increase risk.

Epithelial cells shed into urine and seen on microscopy. Squamous epithelial cells usually reflect normal skin or genital contamination of the sample, while renal tubular epithelial cells in larger numbers can indicate kidney injury. Small numbers are normal.

PED: Epithelial cells are mostly a sample-quality marker rather than a PED concern. A high squamous epithelial count usually means the sample was contaminated by skin or genital cells during collection, which is more likely after training when sweating and rushed collection occur: a clean-catch midstream sample fixes this. Renal tubular epithelial cells are the meaningful subtype, and increased numbers can accompany acute tubular injury, which is relevant if nephrotoxic compounds (high-dose orals, trenbolone, chronic NSAIDs) or rhabdomyolysis are in play.

Acidity or alkalinity of urine, ranging roughly 4.5 to 8.0. Reflects diet, hydration, acid-base status, and certain infections. Useful for assessing kidney stone risk and renal acid handling.

PED: Diet is the dominant driver in athletes. High-protein, meat-heavy diets common in bodybuilding generate sulfuric acid from sulfur-containing amino acids, producing a persistently acidic urine (low pH), which favours uric acid and cystine stone formation. Dehydration during contest prep concentrates urine and compounds stone risk. Persistently alkaline urine can accompany a urea-splitting urinary tract infection (relevant if pyuria or nitrites are present) or vegetarian phases. Creatine and high purine intake can add to uric acid load. Adequate fluid and citrate (from citrus or potassium citrate) help raise pH and reduce stone risk.

Dipstick screen for protein in urine, reported qualitatively (negative, trace, 1+, 2+, 3+). Persistent proteinuria can be an early sign of kidney damage. Normally negative.

PED: Exercise-induced proteinuria is common and benign: strenuous training raises protein excretion for 24-48 hours through changes in glomerular blood flow and oxidative stress, so always test on a rest day. PED-relevant chronic causes matter too: trenbolone, high-dose oral 17-alpha alkylated AAS, and chronic NSAID use can stress renal filtration and produce persistent proteinuria. The dipstick mainly detects albumin and is insensitive to early microalbuminuria, so any positive or borderline result should be followed up with a quantitative spot urine albumin/creatinine ratio (see Urine Albumin and Albumin/Creatinine Ratio).

Dipstick screen for glucose in urine, reported qualitatively (negative, trace, 1+ to 4+). Glucose appears in urine when blood glucose exceeds the renal threshold (around 10 mmol/L) or when the threshold is lowered by medication. Normally negative.

PED: Strong PED relevance. Growth hormone, insulin, and MK-677 (ibutamoren) all raise blood glucose and worsen insulin resistance; sustained hyperglycaemia above the renal threshold (~10 mmol/L) spills glucose into urine. Glycosuria in a GH or insulin user is a red flag for poor glucose control and should prompt fasting glucose, HbA1c, and a review of dosing. Conversely, SGLT2 inhibitors (empagliflozin, dapagliflozin), sometimes used for renal or metabolic protection, cause glycosuria BY DESIGN by lowering the renal glucose threshold, so a positive result is expected and not alarming on these drugs. Always interpret against blood glucose and current medications.

Dipstick screen for ketone bodies (mainly acetoacetate) in urine, reported qualitatively (negative, trace, small, moderate, large). Ketones appear during carbohydrate restriction, fasting, or, dangerously, in uncontrolled diabetes. Normally negative.

PED: Very common and usually benign in bodybuilders. Low-carb and ketogenic dieting, contest prep, fasted training, and extended cardio all push the body into nutritional ketosis, producing trace to moderate urinary ketones with no danger. This benign ketosis occurs with NORMAL or low blood glucose. The alarming scenario is ketones PLUS high blood glucose, which can signal diabetic ketoacidosis (DKA), a medical emergency: this is relevant for athletes using growth hormone, insulin, or MK-677 who develop hyperglycaemia, and for anyone with undiagnosed diabetes. Dehydration during cutting concentrates urine and can exaggerate the dipstick reading.

Dipstick screen that detects haemoglobin AND myoglobin via peroxidase activity, reported qualitatively (negative, trace, 1+ to 3+). A positive result can mean red cells (haematuria), free haemoglobin (haemolysis), or myoglobin (muscle breakdown). Normally negative.

PED: STRONG PED relevance. The blood dipstick cannot distinguish haemoglobin from myoglobin, which is the key athlete pitfall: a positive dipstick with FEW or NO red cells on microscopy points to myoglobinuria from rhabdomyolysis or to haemolysis, not true bleeding. Heavy resistance training, very high muscle mass, severe DOMS, dehydration, and some AAS raise rhabdomyolysis risk; intense weight-bearing exercise can also cause foot-strike (march) haemolysis that releases free haemoglobin. Always cross-reference creatine kinase (markedly elevated in rhabdomyolysis) and the Urine Red Cells microscopy count. Trenbolone, high-dose orals, and NSAID use add renal stress that compounds the risk during a rhabdomyolysis episode.

Ratio of urine albumin to creatinine. The primary screening marker for early kidney damage. Normal: <2.5 mg/mmol (males). Microalbuminuria: 2.5-25. Macroalbuminuria: >25.

PED: CRITICAL kidney health marker for PED users. ACR detects kidney damage earlier than eGFR changes. Trenbolone, high-dose orals (especially anadrol), and chronic NSAID use can impair renal filtration. Heavy training can cause transient elevation — always test on rest days. Serial monitoring is important: a single abnormal result should be confirmed with repeat testing. If persistently elevated alongside declining eGFR, nephrologist referral is warranted.

Calculated ratio of blood urea nitrogen to serum creatinine. Differentiates pre-renal (dehydration) from intrinsic renal causes of azotemia.

PED: CRITICAL CONFOUNDER FOR BODYBUILDERS: High muscle mass raises baseline creatinine (lowering the ratio) while high-protein diets elevate BUN (raising it). These opposing effects partially cancel out, making the ratio unreliable in isolation. Creatine supplementation further elevates creatinine. Dehydration during contest prep or weight cuts disproportionately raises BUN. Always interpret alongside individual BUN, creatinine, eGFR (preferably cystatin C-based), and hydration status. A 'normal' ratio does NOT rule out kidney issues in bodybuilders.

The serum level of oxalate, a metabolic end-product that binds calcium and can form calcium-oxalate crystals, the most common type of kidney stone. Serum oxalate rises when the body overproduces oxalate, absorbs too much from the diet, or clears it poorly in kidney disease.

PED: Kidney-stone risk is a genuine concern for enhanced athletes: very high protein intake, chronic dehydration, high-dose vitamin C (which metabolises to oxalate), and heavy use of spinach/almond-based bodybuilding staples all push oxalate up. Serum oxalate is a spot measure and is most informative in kidney impairment or suspected hyperoxaluria; for stone-risk assessment a 24-hour urine oxalate is usually more useful (see the urine oxalate marker). Athletes who megadose vitamin C should be aware it raises oxalate.

A 24-hour urine collection measuring total oxalate excretion over a full day. This is the preferred test for assessing kidney-stone risk from oxalate, because it captures average excretion rather than a single-moment snapshot like the serum oxalate test. Elevated 24-hour urine oxalate (hyperoxaluria) is a major driver of calcium-oxalate stones.

PED: This is the more actionable of the two oxalate tests for stone-forming athletes. It relates directly to the serum oxalate marker but reflects a full day of intake and metabolism, making it far better for diagnosing dietary or enteric hyperoxaluria. Enhanced athletes accumulate multiple risk factors: high protein and purine load, chronic dehydration from diuretics or hard training, and high-dose vitamin C. A raised 24-hour oxalate points squarely at these modifiable habits.

A measure of how concentrated the urine is, expressed as the ratio of urine density to water (roughly 1.000 to 1.035). It reflects hydration status and the kidney's ability to concentrate urine, and it provides essential context for interpreting other spot-urine readings.

PED: Specific gravity is largely a hydration readout, which makes it very relevant to bodybuilding practices. Diuretic use and water manipulation during contest prep, plus stimulant fat-burners and simple under-drinking, concentrate the urine and push specific gravity high. That concentration is not just a hydration marker: it directly distorts other spot-urine tests. A dipstick protein, glucose, or blood reading looks falsely elevated in highly concentrated urine and falsely reassuring in very dilute urine, so specific gravity should be read first when interpreting a urinalysis. Persistently dilute urine (low specific gravity) despite fluid restriction can point to impaired concentrating ability. Aggressive dehydration for stage or weigh-ins also raises kidney-stone risk. Values are lab and refractometer dependent.

A breakdown product of bilirubin formed by gut bacteria; a small amount is reabsorbed and appears normally in urine. Small quantities are expected, so both a modest positive and a negative can be normal. Markedly increased levels point to increased bilirubin turnover or impaired hepatic handling.

PED: Urine urobilinogen rises in two situations relevant to enhanced athletes: haemolysis (increased red-cell breakdown delivers more bilirubin to the gut) and liver dysfunction (a strained liver clears less reabsorbed urobilinogen). Oral 17-alpha-alkylated AAS impose real hepatic strain, so an elevated urine urobilinogen alongside raised ALT/AST, GGT, or bilirubin adds to the picture of AAS-related cholestasis or hepatocellular stress and is worth heeding. Conversely, a completely absent urobilinogen with pale stools and dark urine can suggest biliary obstruction. It is a crude screening finding, not a standalone diagnosis: always confirm with serum liver enzymes, bilirubin (total, direct, indirect), and a haemolysis workup (haptoglobin, LDH, reticulocytes) rather than acting on the dipstick alone.

Primary male sex hormone. Important for muscle growth, bone density, and mood.

PED: Exogenous testosterone will show supraphysiological levels while on cycle. It suppresses the HPT axis: GnRH from the hypothalamus drops, causing LH and FSH from the pituitary to fall, removing the signal for endogenous production. After cycle without PCT, levels are severely suppressed (often <1 nmol/L) and recovery can take months. TRT doses typically target 20-30 nmol/L. Natural range 8-30 nmol/L.

Testosterone that is free or loosely bound to albumin. Represents the portion available to tissues (free T + albumin-bound T).

PED: Bioavailable testosterone includes both free testosterone and albumin-bound testosterone (which can readily dissociate). It excludes only SHBG-bound testosterone. This is a more comprehensive measure of 'usable' testosterone than free T alone. Common on US lab panels (Quest, LabCorp) where it's reported in ng/dL. On AAS/TRT, bioavailable T will be elevated proportionally to total T, modified by SHBG status.

Unbound, biologically active testosterone. More clinically relevant than total.

PED: More meaningful than total testosterone as it reflects bioavailable hormone. SHBG levels affect free testosterone significantly. AAS that lower SHBG can increase free testosterone disproportionately.

Primary estrogen. Important for bone health, lipids, and cardiovascular protection.

PED: Aromatizable AAS (testosterone, dianabol, nandrolone) increase estradiol. CRITICAL: Elevated E2 in enhanced athletes should be managed by SYMPTOMS, not numbers alone. Estradiol is cardioprotective, neuroprotective, essential for libido, joint health, and lipid profiles -- crashing it causes more harm than running it high. Symptoms of genuinely problematic high E2: sensitive/puffy nipples or gyno onset, excessive water retention and bloating, emotional instability or anxiety, erectile dysfunction or loss of libido, elevated blood pressure from fluid retention. If E2 is elevated but no symptoms are present, do NOT intervene. Optimal TRT range is 70-180 pmol/L but many enhanced athletes run higher without issues.

Pituitary hormone that stimulates testosterone production in testes.

PED: Will be completely suppressed (<0.5) while on any AAS or exogenous testosterone. Used to confirm HPTA suppression/recovery. HCG mimics LH so can maintain testicular function on cycle.

Pituitary hormone important for sperm production.

PED: Suppressed by exogenous AAS. Important for fertility considerations. Recovery of FSH post-cycle indicates HPTA is recovering.

Protein that binds sex hormones, reducing their bioavailability.

PED: Many oral AAS dramatically lower SHBG (especially Proviron, Winstrol, Anavar). Low SHBG increases free testosterone percentage. Very low SHBG can indicate oral AAS use even if testosterone appears 'normal'.

Hormone from pituitary gland. Elevated levels can affect sexual function and mood.

PED: 19-nor compounds (Nandrolone, Trenbolone) can significantly elevate prolactin. High prolactin causes sexual dysfunction (erectile issues, anorgasmia), gyno risk, and in extreme cases lactation. Should be monitored on any 19-nor cycle. If prolactin is elevated without 19-nor use, investigate pituitary function.

Steroid hormone involved in reproductive function, neuroprotection, and immune modulation. In males, produced mainly by the adrenal glands and testes.

PED: Suppressed by exogenous AAS due to HPTA shutdown. Low progesterone on cycle is expected. 19-nor compounds (Nandrolone, Trenbolone) have progestogenic activity and can cause progesterone-like side effects despite low serum levels. Relevant for assessing HPTA recovery in PCT.

Marker for prostate health. Elevated levels warrant investigation for prostate issues.

PED: AAS use, particularly DHT derivatives, can elevate PSA. Important to monitor regularly when using androgens. Elevated PSA doesn't always mean cancer but needs investigation.

The unbound (free) fraction of prostate-specific antigen circulating in serum. Total PSA exists in two main forms: complexed PSA (bound to plasma proteins, mostly alpha-1-antichymotrypsin) and free PSA (unbound). Free PSA is most useful when interpreted alongside total PSA as the percent free PSA ratio (see `psa-free-percent`). Reflexed by many labs when total PSA is in the 4 to 10 ug/L grey zone.

PED: Free PSA on its own has limited interpretation; what matters clinically is the ratio of free to total PSA (percent free PSA). The reflex Free PSA test is typically ordered when total PSA falls in the 4 to 10 ug/L diagnostic grey zone, where the free / total ratio helps distinguish benign prostatic hyperplasia (BPH) from prostate cancer. Bodybuilders on DHT-derivative AAS (Masteron, Primobolan, Anavar, Winstrol, Proviron) and high-dose testosterone often see total PSA elevation; in this context a Free PSA reflex test plus the percent free ratio can help separate PED-driven prostatic stimulation from cancer-suspicious patterns. Free PSA itself is not a screening test.

Ratio of Free PSA to Total PSA, expressed as a percentage: (Free PSA / Total PSA) × 100. The clinically actionable number that comes out of a reflex Free PSA test. Used to refine cancer risk when Total PSA is in the 4 to 10 ug/L diagnostic grey zone. Lower percentages indicate higher prostate cancer probability.

PED: Most useful when Total PSA is between 4 and 10 ug/L. In that range, percent free PSA below 10% suggests roughly 50% probability of prostate cancer on biopsy, while above 25% drops the probability to roughly 8% (Catalona 1998). For bodybuilders with PED-driven Total PSA elevation (DHT derivatives, high-dose testosterone), a high percent free PSA is reassuring evidence that the elevation reflects prostatic stimulation rather than malignancy. A low percent free PSA in this same context still warrants urology referral; PED use does not override the cancer signal in the ratio.

Growth factor produced primarily by the liver in response to growth hormone (GH). Reflects overall GH secretion and mediates many of GH's anabolic effects. Age- and sex-specific reference ranges apply.

PED: CRITICAL marker for GH use monitoring. Exogenous GH directly elevates IGF-1 — the primary way to confirm GH is working and dose-response. Supraphysiological IGF-1 (>1.5x upper limit) indicates high GH dosing and increases risk of insulin resistance, soft tissue growth, and long-term cancer risk. AAS alone do not significantly affect IGF-1. Insulin co-administration with GH further amplifies IGF-1 levels. Target for health-conscious GH use: upper-normal range (25-35 nmol/L). Recheck 4-6 weeks after dose changes. Fasting state and time since last GH injection affect levels.

Age- and sex-adjusted standardised score for IGF-1, expressed in standard deviations from the population mean. A z-score of 0 represents the age-matched median, +1 represents one standard deviation above the mean, and -1 represents one standard deviation below. Removes the age-decline confounder that complicates raw IGF-1 interpretation across the lifespan.

PED: The cleanest way to interpret IGF-1 on GH or peptide protocols. Raw IGF-1 ng/mL or nmol/L values cannot be compared across age groups because endogenous IGF-1 falls roughly 1-2% per year after age 30. A 250 ng/mL value at age 25 is high-normal; the same value at age 65 is supraphysiological. The z-score normalises against the age-matched reference, making it the right number to monitor when running tesamorelin, CJC-1295 plus ipamorelin, MK-677, or exogenous HGH. The FDA tesamorelin label uses z-score (SDS) thresholds: dose reduction at z >2 SDS sustained, discontinuation at z >3 SDS. Bidlingmaier et al. (PMID 24432983) published the largest IGF-1 reference dataset (n=15,014) for z-score calculation by Roche immunoassay; LabCorp, Quest, and Mayo all derive their reference ranges from comparable population datasets.

Pituitary hormone that stimulates growth, cell reproduction, and regeneration. Basal fasting levels are typically low; GH is secreted in pulses. Single measurements have limited diagnostic value without stimulation/suppression testing.

PED: Exogenous GH use will elevate random serum GH levels. Basal fasting GH < 1 mIU/L is typical for adult males not on GH. IGF-1 is a more reliable marker for monitoring GH status since it reflects integrated 24h GH secretion. Timing of blood draw relative to last GH injection significantly affects results.

Primary stress hormone produced by the adrenal cortex. Regulates metabolism, immune response, and blood pressure. Levels follow a diurnal pattern (highest in the morning).

PED: Elevated by intense training, caloric deficit, and psychological stress. Chronically elevated cortisol is catabolic and impairs recovery. Some AAS (especially Trenbolone) can increase cortisol-related symptoms. Timing of blood draw significantly affects results -- morning fasting samples are standard.

Mineralocorticoid hormone produced by the adrenal zona glomerulosa. Regulates sodium retention, potassium excretion, and blood pressure as the final effector of the renin-angiotensin-aldosterone system (RAAS).

PED: Highly relevant to enhanced athletes who already battle hypertension and fluid retention. Primary aldosteronism is a common, under-diagnosed cause of resistant high blood pressure and should be considered in any AAS user with hard-to-control hypertension, especially alongside low or low-normal potassium. High dietary sodium and the mineralocorticoid-like sodium-retaining activity of some AAS drive fluid retention and blood pressure on cycle. Licorice (glycyrrhizin) mimics aldosterone and can produce a similar picture with suppressed aldosterone. Always interpret aldosterone with renin and the aldosterone-renin ratio (ARR), and note that results are strongly posture and time dependent.

Enzyme released by the juxtaglomerular cells of the kidney that initiates the renin-angiotensin-aldosterone system (RAAS). Reported either as direct renin concentration (mIU/L) or as plasma renin activity (ng/mL/h).

PED: A key partner test to aldosterone when investigating hypertension in enhanced athletes. Suppressed renin together with high aldosterone (a raised aldosterone-renin ratio) signals primary aldosteronism, a treatable cause of resistant high blood pressure. Renin is heavily influenced by drugs many athletes use: beta-blockers and NSAIDs lower it, while ACE inhibitors, angiotensin receptor blockers, and diuretics raise it. Posture, salt intake, time of day, and potassium all shift the result, so collection must be standardised.

Calculated ratio of aldosterone to renin used as the screening test for primary aldosteronism. The numeric value and its cutoff depend entirely on the units used for aldosterone and for renin.

PED: This is the single most useful screen when an enhanced athlete has hypertension plus low or low-normal potassium. A raised ARR (high aldosterone relative to a suppressed renin) flags possible primary aldosteronism, a common and treatable driver of resistant high blood pressure. The ratio must be interpreted with posture, time of day, potassium status, and a review of interfering medications; a single abnormal ARR is a screen, not a diagnosis, and needs confirmatory testing.

Pituitary hormone that drives cortisol production by the adrenal cortex. Interpreted alongside cortisol to evaluate the hypothalamic-pituitary-adrenal (HPA) axis. Follows a diurnal rhythm, highest in the early morning.

PED: Directly relevant after any glucocorticoid use. Exogenous glucocorticoids (oral, injected, or even high-dose inhaled/topical) suppress ACTH and can cause adrenal suppression that persists for weeks to months after stopping. Athletes who run prednisone, dexamethasone, or frequent corticosteroid joint injections, or who use compounds with HPA-suppressing effects, can present with fatigue and low cortisol once the steroid is withdrawn. Pair ACTH with cortisol: low cortisol with low or inappropriately normal ACTH points to secondary or tertiary (pituitary/hypothalamic) adrenal insufficiency, while low cortisol with high ACTH points to primary adrenal failure (Addison's). Collect in the early morning.

Adrenal androgen precursor. Most abundant circulating steroid. Declines with age. Reflects adrenal androgen production.

PED: Exogenous AAS suppress HPTA but DHEA-S is primarily adrenal, so it may remain relatively stable on cycle. Low DHEA-S can indicate adrenal insufficiency or chronic stress. Some athletes supplement DHEA as a mild androgen precursor during PCT.

Adrenal and gonadal androgen precursor. Sits one step upstream of testosterone and converts to testosterone, estrone, and estradiol. The classic 'andro' prohormone.

PED: Rises with DHEA and androstenedione (prohormone) supplementation, which historically were marketed to raise testosterone. On exogenous testosterone or other AAS, endogenous androstenedione is suppressed alongside the rest of the HPG axis (LH and FSH shut down, gonadal output falls), so an on-cycle value reflects suppression rather than true adrenal status. Because androstenedione aromatises to estrone and estradiol, elevated levels can worsen estrogenic side effects (water retention, gynaecomastia risk). It is also a screening marker for congenital adrenal hyperplasia (CAH) and is useful during PCT or natural recovery to gauge returning androgen precursor production.

Potent androgen converted from testosterone by 5-alpha reductase. Responsible for male sexual development, prostate growth, and androgenic effects including hair loss.

PED: DHT is 3-5x more androgenic than testosterone. Elevated by exogenous testosterone (more substrate for 5-alpha reductase) and by DHT-derivative compounds (Masteron, Primobolan, Anavar, Winstrol). High DHT drives androgenic side effects: male pattern hair loss, acne, prostate enlargement, and body hair growth.

Ratio of total testosterone to estradiol, converted to conventional units (T ng/dL / E2 pg/mL). Reflects the androgenic-to-estrogenic balance. A low ratio indicates relative estrogen dominance; a very high ratio suggests over-suppressed estradiol.

PED: Auto-calculated when both Testosterone and Estradiol are present in a blood test. IMPORTANT: This ratio is a guide, not a treatment target — E2 management should always be symptom-based. A ratio below 10 suggests significant estrogen dominance and may correlate with gyno risk, water retention, mood issues, and ED. A ratio above 40 suggests E2 may be too low relative to T, risking joint pain, poor libido, worsened lipids, and bone density loss. On TRT doses (100-200mg/week), typical ratios are 20-40. On blast doses, the ratio often drops below 20 because aromatization increases disproportionately at supraphysiological testosterone levels — this is expected and acceptable if asymptomatic. Studies show men with very low E2 (ratio >50) have 3x higher mortality than those with moderately elevated E2 (ratio 15-25). Do not chase a specific number — treat symptoms, not the ratio.

Ratio of total testosterone to SHBG, expressed as a percentage: (Total T / SHBG) × 100. Estimates the proportion of bioavailable testosterone. More useful than total T alone because SHBG status dramatically affects androgen exposure.

PED: Auto-calculated when both Testosterone and SHBG are present in a blood test. Normal male range is 30-150%. On AAS/TRT, FAI is typically very high (>200%) — this is expected and not actionable. The main clinical utility is off-cycle or on TRT: a low FAI (<30%) despite normal total T points to high SHBG as the cause of hypogonadal symptoms (low libido, erectile dysfunction, fatigue, poor recovery). On oral AAS that crush SHBG (Anavar, Winstrol, Proviron), FAI can be extremely high (>500%) even with moderate total T — this means high free androgen exposure and explains androgenic side effects despite 'normal' total T levels.

Ratio of luteinizing hormone (LH) to follicle-stimulating hormone (FSH). In men, both gonadotropins are normally suppressed in parallel by exogenous androgens, so the ratio stays close to 1. A skewed ratio off-cycle or during PCT carries diagnostic information about HPTA recovery, primary versus secondary hypogonadism, and the relative balance of FSH versus LH stimulation.

PED: Auto-calculated when both LH and FSH are present. On any AAS or TRT cycle, both LH and FSH are usually suppressed below the detectable limit; the ratio is meaningless in that state. The ratio becomes interpretable off-cycle, during PCT, or in a workup of secondary hypogonadism. A normal off-cycle male ratio is approximately 0.5 to 1.5 (FSH and LH in similar magnitude). A persistently high LH with low FSH suggests primary Sertoli cell dysfunction (FSH should rise to compensate but does not, sometimes seen in long-term AAS users with damaged spermatogenesis). A high FSH with normal LH is the classic pattern of testicular failure with preserved Leydig function. Useful in PCT to confirm both gonadotropins are returning, not just LH.

Hormone secreted by the parathyroid glands that regulates calcium and phosphate balance. PTH raises serum calcium by stimulating bone resorption, increasing renal calcium reabsorption, and activating Vitamin D (1,25-dihydroxyvitamin D) to boost intestinal calcium absorption.

PED: Not directly affected by AAS, but highly relevant to bodybuilders because Vitamin D deficiency (common in gym-based athletes with limited sun exposure) drives secondary hyperparathyroidism. Chronically elevated PTH from low Vitamin D accelerates bone turnover and may blunt the anabolic benefits of AAS on bone. GH and IGF-1 interact with PTH to modulate bone remodelling. Always interpret alongside serum Calcium, Vitamin D (25-OH), and Phosphate, never in isolation.

An intermediate steroid in the adrenal and gonadal steroidogenesis pathway, produced from progesterone and pregnenolone and converted onward toward cortisol and androgens. Its main clinical use is screening for 21-hydroxylase deficiency (non-classic congenital adrenal hyperplasia, CAH).

PED: Relevant to AAS users on two fronts. First, exogenous androgens and glucocorticoid-like compounds suppress the HPA and HPG axes, which can lower endogenous 17-OHP; a suppressed value on cycle is expected and not itself alarming. Second, an unexpectedly elevated 17-OHP in someone with hirsutism, acne, or fertility problems can flag non-classic CAH, which changes how androgen excess should be managed. Draw in the early morning (levels are highest around 8am) and, in cycling athletes, ideally at a hormonal baseline off suppressive compounds.

The upstream precursor of all steroid hormones, synthesised from cholesterol and sitting at the top of the pathway that branches toward DHEA and the androgens on one side and progesterone, cortisol, and aldosterone on the other. Also acts as a neurosteroid.

PED: Sometimes supplemented by bodybuilders on the theory that boosting the master precursor raises downstream DHEA and testosterone, but the evidence for that cascade in men is weak: supplemental pregnenolone reliably raises pregnenolone and its sulfate but does not consistently lift testosterone. On AAS, endogenous pregnenolone is typically suppressed along with the rest of the axis. Note this platform already suggests pregnenolone 25-50mg/day as an adjunct elsewhere (see the DHEA marker); this entry tracks the measured serum level rather than the supplement.

The quantitative serum measurement of the beta subunit of human chorionic gonadotropin. This is a diagnostic blood test used to detect pregnancy and, in men and non-pregnant women, to screen for certain germ-cell and trophoblastic tumours. It is distinct from the injectable hCG drug that bodybuilders use: this entry is the lab measurement of the hormone in your blood, not a compound you administer.

PED: Important not to confuse this lab test with hCG the drug. Many AAS users inject hCG to maintain testicular function or during PCT, and doing so will produce a positive/elevated serum beta-hCG on this test, which is expected and not a cause for alarm. In a man who is NOT using hCG, a persistently elevated beta-hCG is abnormal and warrants investigation for a testicular germ-cell tumour, so knowing your own hCG use is essential to interpret the result. If you have injected hCG, note the timing: it can remain detectable for days to a couple of weeks depending on dose and ester.

An adipose-derived hormone that signals the size of the body's fat stores to the hypothalamus, suppressing appetite and permitting normal reproductive and thyroid function when energy stores are adequate. Levels track body fat closely and fall sharply with fat loss and energy restriction.

PED: Leptin is largely a readout of fat mass and energy availability, and women run markedly higher levels than men at the same body-fat percentage. In lean, dieting, or contest-prep athletes leptin drops to very low levels: this is expected, not pathological, but it is the central signal behind metabolic adaptation (falling NEAT, blunted thyroid output, suppressed LH and testosterone, relentless hunger). A near-zero leptin in a stage-lean competitor simply confirms an aggressive deficit. On the other end, high leptin with obesity reflects leptin resistance rather than deficiency. GLP-1 agonists and MK-677 both interact with appetite signalling, and refeeds or diet breaks that transiently raise leptin are used to blunt the starvation response. There is no meaningful role for measuring leptin to guide AAS use.

A single measurement of the combined pool of oestrogens in serum: oestrone (E1), oestradiol (E2), and oestriol (E3) together. It is an older, less specific panel that reports the sum rather than any individual hormone.

PED: IMPORTANT: Total Estrogens is NOT interchangeable with Estradiol (E2) and should not be treated as your E2 number. Because it lumps oestrone, oestradiol, and oestriol together, it cannot tell you the E2 level that actually matters for men on TRT or AAS, and it can read high from oestrone even when E2 is fine, or obscure a genuinely high E2. For anyone managing oestrogen on cycle or deciding on an aromatase inhibitor, the correct test is a sensitive (LC-MS/MS) Estradiol assay, which this knowledge base tracks separately. If a lab has reported Total Estrogens, ask for a sensitive Estradiol instead before making any AI dosing decision. In women, total oestrogens vary widely across the menstrual cycle and reproductive stage, so a single value is hard to interpret without cycle context.

Total amount of cholesterol in the blood.

PED: AAS generally worsen lipid profiles. Oral AAS are particularly harsh on lipids. Total cholesterol alone is less meaningful than the HDL/LDL ratio and ApoB.

High-density lipoprotein - 'good' cholesterol that protects against heart disease.

PED: CRITICAL: AAS (especially oral compounds) dramatically suppress HDL, often to dangerously low levels (<0.5 mmol/L). This is one of the most significant cardiovascular risks of AAS use. HDL should be monitored closely and given time to recover between cycles. HDL typically takes 4-8 weeks to recover after dropping oral compounds.

Low-density lipoprotein - 'bad' cholesterol associated with heart disease risk.

PED: AAS typically elevate LDL. Combined with suppressed HDL, this creates an atherogenic profile. ApoB is a more accurate measure of atherogenic particle count than LDL alone.

Type of fat in the blood. Elevated levels increase cardiovascular risk.

PED: Can be elevated by high calorie bulking diets, especially high carb. GH use can worsen triglycerides. Fasted blood draw important for accurate reading (12h fast minimum).

Total cholesterol minus HDL. Captures all atherogenic lipoproteins (LDL, VLDL, IDL).

PED: Better predictor of cardiovascular risk than LDL alone. AAS worsen this marker by suppressing HDL and elevating LDL/VLDL. Target <2.5 mmol/L for primary prevention. ApoB is an even more accurate cardiovascular risk marker -- consider requesting alongside lipid panel.

Ratio of total cholesterol to HDL. Lower is better for cardiovascular health.

PED: AAS users often have very unfavourable ratios due to suppressed HDL. Ratio >5.0 indicates elevated cardiovascular risk. Optimal is <4.0.

Protein found on all atherogenic lipoprotein particles (LDL, VLDL, IDL, Lp(a)). Each particle carries exactly one ApoB molecule, making it a direct count of atherogenic particles. Considered a more accurate cardiovascular risk predictor than LDL alone.

PED: Superior to LDL for assessing cardiovascular risk in PED users. AAS worsen ApoB levels -- oral compounds are particularly harmful. Unlike LDL (which measures cholesterol content), ApoB counts the actual number of atherogenic particles, which better predicts arterial plaque buildup. Target <0.9 g/L for primary prevention, <0.7 g/L for high-risk individuals.

Genetically determined lipoprotein particle. Elevated levels are an independent risk factor for cardiovascular disease, aortic stenosis, and stroke. Levels are ~90% determined by genetics and largely unaffected by lifestyle.

PED: Lp(a) is almost entirely genetic -- AAS, diet, and exercise have minimal effect on levels. However, it is a critical cardiovascular risk marker that every PED user should know once. If elevated (>75 nmol/L or >30 mg/dL), it compounds the already elevated cardiovascular risk from AAS-worsened lipids. Test once -- if normal, no need to retest as levels are stable throughout life.

The primary structural protein of HDL particles. Superior predictor of cardiovascular risk compared to HDL-C because it directly quantifies functional HDL particles.

PED: Oral 17-alpha-alkylated AAS devastate ApoA-1. Stanozolol reduced ApoA-1 by 40% in clinical studies — it upregulates hepatic triglyceride lipase (HTGL) by 230% within 3 days, accelerating HDL catabolism. Injectable testosterone at TRT doses has minimal effect. Nandrolone showed no significant change. Compounds ranked worst to least: Stanozolol > Oxandrolone > Oxymetholone > Trenbolone > Boldenone > Testosterone > Nandrolone. Recovery is slow — ApoA-1 had not returned to baseline 6 weeks after a 14-week cycle.

The balance between atherogenic particles (ApoB) and protective particles (ApoA-1). Considered the single most powerful lipid predictor of cardiovascular risk, superior to any cholesterol ratio.

PED: AAS users get a double hit — ApoB rises (more atherogenic particles) while ApoA-1 drops (fewer protective particles), amplifying the ratio dramatically. A baseline of 0.55 can easily reach 1.2+ on an oral AAS cycle. The INTERHEART study (52 countries) found ApoB/ApoA-1 superior to any cholesterol ratio for predicting myocardial infarction, with a population-attributable risk of 54%. This is the most important single lipid marker for PED users to track.

Total number of LDL particles measured by NMR spectroscopy. More predictive of cardiovascular disease than LDL cholesterol concentration alone.

PED: AAS significantly increase LDL particle number, even when LDL-C appears only mildly elevated. Oral 17-alpha-alkylated steroids have the most pronounced effect. Discordance between LDL-C and LDL-P is common in AAS users — LDL-P often reveals higher cardiovascular risk than LDL-C suggests. Combined with HDL suppression, this creates a highly atherogenic particle profile. Trenbolone is particularly harsh on lipoprotein particle counts.

Mean diameter of LDL particles. Pattern A (large buoyant, >20.5 nm) is less atherogenic; Pattern B (small dense, <20.5 nm) is associated with increased cardiovascular risk.

PED: AAS shift LDL toward small dense Pattern B particles, increasing atherogenicity even when total LDL-C is not dramatically elevated. Oral AAS (stanozolol, oxandrolone) cause the most pronounced shift to small dense LDL. Insulin resistance from GH/insulin use compounds this shift. High triglycerides correlate with smaller LDL. Pattern B + elevated LDL-P is the most concerning combination.

Total number of HDL particles. HDL-P is a stronger predictor of cardiovascular protection than HDL cholesterol concentration.

PED: AAS profoundly suppress HDL-P, often more dramatically than HDL-C. Oral AAS cause the most severe suppression. HDL-P is a better measure of reverse cholesterol transport capacity than HDL-C alone. On-cycle HDL-P values of 15-20 umol/L are common (vs normal >30). Recovery of HDL-P after cycle cessation can take 3-6 months.

Concentration of large VLDL particles. Elevated levels indicate triglyceride-rich lipoprotein overproduction and are strongly linked to insulin resistance.

PED: GH use increases hepatic VLDL production, elevating large VLDL-P. Insulin use (common in advanced bodybuilding) and insulin resistance from GH compound this. High-calorie bulking diets (especially high-carb) drive VLDL production. Oral AAS affect hepatic lipid metabolism, contributing to VLDL elevation. Elevated large VLDL-P correlates strongly with the LP-IR score.

Concentration of large HDL particles. These are the most cardioprotective HDL subclass, responsible for the majority of reverse cholesterol transport.

PED: AAS profoundly reduce large HDL-P — these particles are the first to decline on-cycle. Oral AAS have the most severe impact. Large HDL-P is the HDL subclass most associated with cardiovascular protection. On-cycle values often drop to near-zero. Recovery after cycle cessation is slow (3-6 months). Aerobic exercise is the strongest stimulus for large HDL-P production.

Mean diameter of VLDL particles. Larger VLDL particles are more triglyceride-rich and associated with insulin resistance and metabolic dysfunction.

PED: GH use and insulin resistance increase VLDL size by promoting hepatic production of large triglyceride-rich VLDL. High-calorie bulking diets (especially high-carb) increase VLDL size. Larger VLDL particles are a key driver of the LP-IR insulin resistance score. Combined with insulin and GH use in advanced bodybuilding, VLDL size can be significantly elevated.

Mean diameter of HDL particles. Larger HDL particles are more cardioprotective, associated with better reverse cholesterol transport capacity.

PED: AAS shrink HDL particles by reducing the proportion of large cardioprotective HDL. Smaller HDL is less effective at reverse cholesterol transport. Oral AAS have the most pronounced effect on HDL size. Regular aerobic exercise promotes larger HDL particles. HDL size typically recovers post-cycle alongside HDL-C and HDL-P.

NMR-derived composite score (0-100) reflecting insulin resistance based on lipoprotein particle sizes and concentrations. Higher scores indicate greater insulin resistance.

PED: GH use induces insulin resistance, directly elevating the LP-IR score. Exogenous insulin use (common in advanced bodybuilding) creates a complex picture — insulin sensitivity may be adequate but the lipoprotein profile reflects resistance patterns. Bulking phases with high carbohydrate intake worsen LP-IR. AAS themselves have variable effects on insulin sensitivity, but the combined GH + AAS + high-calorie diet profile commonly seen in bodybuilders often produces elevated LP-IR scores. This marker integrates information from VLDL, LDL, and HDL particle sizes and subclass concentrations.

Calculated ratio of LDL to HDL cholesterol. A higher ratio indicates greater atherogenic risk. Useful as a quick cardiovascular risk assessment.

PED: AAS dramatically worsen this ratio through a dual mechanism: elevating LDL while simultaneously suppressing HDL. Oral 17-alpha-alkylated steroids cause the most severe distortion — ratios of 5-10+ are common on-cycle (vs ideal <2.5). Trenbolone is particularly harsh. Even injectable testosterone at supraphysiological doses worsens this ratio. Post-cycle recovery of this ratio depends primarily on HDL recovery, which can take 3-6 months.

Cholesterol carried by VLDL particles, which transport triglycerides from the liver. Usually estimated from triglycerides via the Friedewald equation (Triglycerides / 5 in mg/dL). Elevated levels indicate excess triglyceride-rich lipoprotein production and increased atherogenic risk.

PED: Oral/17-alpha-alkylated AAS (oxandrolone, stanozolol, methandrostenolone) increase hepatic VLDL production while suppressing HDL, creating a broadly atherogenic profile. GH stimulates hepatic VLDL secretion by enhancing lipolysis and promoting insulin resistance. The combination of oral AAS + GH + high-calorie bulking diets creates maximal VLDL elevation through multiple converging pathways. Lipid effects from AAS are generally reversible, normalising 2.5 to 4 months after discontinuation.

The ratio of fasting triglycerides to HDL cholesterol. Serves as an accessible proxy for insulin resistance and small dense LDL particle predominance. A ratio above 2.0 is associated with insulin resistance and elevated cardiovascular risk; above 3.5 is strongly predictive of metabolic syndrome. Lower is better.

PED: AAS users face a compounded problem: androgens, especially oral compounds, suppress HDL (raising the denominator problem) while high-calorie bulking diets and GH-related insulin resistance elevate triglycerides. MK-677, by chronically elevating GH and IGF-1, produces insulin resistance that worsens fasting triglycerides substantially, often pushing the ratio above 3.0 even without traditional AAS. This ratio is more informative in PED users than in the general population because it integrates both lipid and metabolic dysfunction simultaneously.

Calculated as Total Cholesterol minus LDL minus HDL. Represents the cholesterol content of triglyceride-rich lipoprotein remnants: primarily VLDL remnants (IDL) and chylomicron remnants. An emerging cardiovascular risk marker that predicts atherosclerosis independently of LDL. Desirable level is below 0.5 mmol/L.

PED: AAS broadly disrupt lipoprotein metabolism, increasing hepatic VLDL production and impairing VLDL clearance, which elevates remnant cholesterol even when LDL appears acceptable. GH therapy significantly raises VLDL secretion, directly increasing remnant cholesterol. The Copenhagen Heart Study and Mendelian randomisation data confirm remnant cholesterol predicts cardiovascular events independently of LDL, making it a valuable additional marker for PED users who may have normal LDL but disturbed VLDL metabolism.

Calculated by dividing LDL cholesterol (in mg/dL or mmol/L converted) by ApoB (in mg/dL). Estimates LDL particle size distribution. A ratio above 1.2 suggests predominance of large buoyant LDL particles (less atherogenic); below 1.2 suggests small dense LDL predominance (more atherogenic). Does not require a fasted sample.

PED: AAS users tend toward small dense LDL (pattern B) due to elevated triglycerides and reduced HDL, which activate CETP-mediated cholesterol ester transfer from LDL to VLDL, producing smaller, denser LDL particles. A PED user with LDL of 3.5 mmol/L and an LDL/ApoB ratio of 0.9 has a significantly worse cardiovascular risk profile than someone with the same LDL and a ratio of 1.3. This ratio provides actionable context for interpreting LDL in the setting of AAS-altered lipoprotein metabolism. Units note: when using mmol/L for LDL and g/L for ApoB, multiply LDL by 38.67 to convert to mg/dL for this calculation.

A long-chain omega-3 fatty acid, measured here as its percentage of total fatty acids on a red-blood-cell or plasma fatty-acid panel. EPA is strongly anti-inflammatory and, with DHA, underlies the cardioprotective effects attributed to marine omega-3s.

PED: A low EPA percentage indicates poor omega-3 status and typically tracks with a high omega-6 to omega-3 balance, which is pro-inflammatory. This matters for enhanced athletes on two fronts: AAS worsen the lipid and cardiovascular profile, and raising EPA (via oily fish or fish-oil supplementation) is one of the few evidence-based levers that lowers triglycerides and systemic inflammation without harming the physique. EPA percentage climbs predictably with EPA/DHA intake, so it is a useful way to confirm supplementation is actually working. Values are matrix and method dependent (red-cell panels read differently from plasma), so compare against the reporting lab's range and trend it over time.

A long-chain omega-3 fatty acid measured as a percentage of total fatty acids on a red-blood-cell or plasma panel. DHA is a major structural fat in neural and retinal membranes and, with EPA, drives the cardiovascular and anti-inflammatory benefits of marine omega-3s.

PED: DHA percentage is a marker of omega-3 status and, together with EPA, forms the basis of the Omega-3 Index. A low DHA reflects inadequate marine omega-3 intake and a pro-inflammatory fatty-acid balance. For AAS users, whose lipids and cardiovascular risk are already worsened, improving DHA/EPA status is a cheap, evidence-based support measure that lowers triglycerides and inflammation. DHA is raised most efficiently by oily fish or fish/algal oil. As with all fatty-acid percentages, results depend on the panel matrix (red cell vs plasma), so trend against the same lab's reference.

An intermediate long-chain omega-3 fatty acid that sits metabolically between EPA and DHA. Measured as a percentage of total fatty acids, it acts as a reservoir that can be converted to EPA or DHA and contributes to overall omega-3 status.

PED: DPA is the less-discussed third marine omega-3, alongside EPA and DHA, and it is included in the EPA+DPA+DHA sum that some panels report as their Omega-3 Index. It rises with fish and fish-oil intake and generally moves in parallel with EPA and DHA, so a low DPA usually just reinforces a low overall omega-3 status. There is no separate supplement target for DPA specifically: improving total EPA/DHA intake raises it. As with the other fatty-acid fractions, the percentage is matrix and method dependent.

The principal long-chain omega-6 fatty acid, measured as a percentage of total fatty acids. It is the substrate for many pro-inflammatory eicosanoids, and its level relative to EPA (the AA/EPA ratio) is a widely used index of the body's inflammatory fatty-acid balance.

PED: Arachidonic acid is not villainous in itself: it is essential for membrane function and, in the training world, is even used as a supplement to amplify the inflammatory signalling that supports muscle hypertrophy. The issue for cardiovascular and general inflammatory status is balance, specifically AA relative to EPA. A high AA percentage with a low EPA percentage (a high AA/EPA ratio) reflects a pro-inflammatory milieu, which is unhelpful on top of the cardiovascular strain AAS already impose. The lever is not usually to cut AA but to raise EPA/DHA so the ratio improves. Values are matrix and method dependent.

The most abundant dietary omega-6 fatty acid and an essential fat, measured as a percentage of total fatty acids. It is the parent omega-6 from which arachidonic acid can be synthesised, and it typically makes up a large share of the fatty-acid profile.

PED: Linoleic acid is essential and comes from seed oils, nuts, and seeds, so most people have plenty. On a fatty-acid panel it is usually one of the largest fractions. Contrary to the simple omega-6-is-bad narrative, higher circulating linoleic acid is generally associated with neutral-to-favourable cardiometabolic outcomes; the pro-inflammatory concern applies more to the downstream omega-6 to omega-3 balance than to linoleic acid itself. For enhanced athletes the practical point is simply to keep the overall omega-6 to omega-3 ratio in check by ensuring adequate EPA/DHA, rather than fixating on linoleic acid. Values are matrix and method dependent.

The summed percentage of all omega-3 fatty acids on the panel (typically ALA, EPA, DPA, and DHA) as a fraction of total fatty acids. It is a broad measure of overall omega-3 status, related to but not identical to the Omega-3 Index.

PED: Omega-3 Total is the panel's overall omega-3 sum. It is closely related to the Omega-3 Index but not the same thing: the Omega-3 Index counts specifically red-cell EPA+DHA (some panels EPA+DPA+DHA), whereas the total may also include the plant omega-3 ALA, which is far less biologically active. So a respectable Omega-3 Total driven by ALA can still coexist with a low, suboptimal Omega-3 Index. For cardiovascular purposes the marine EPA/DHA content is what matters, and a red-cell EPA+DHA of about 8% or higher is the cardioprotective target. For AAS users, improving marine omega-3 status is a legitimate, low-cost cardiovascular support measure. Values are matrix and method dependent.

The summed percentage of all omega-6 fatty acids on the panel (chiefly linoleic acid and arachidonic acid) as a fraction of total fatty acids. Omega-6 fats are essential but, in a Western diet, usually abundant, so the informative figure is the omega-6 to omega-3 ratio rather than the total alone.

PED: Omega-6 fats are essential and typically plentiful, so a high Omega-6 Total by itself is rarely the problem; what matters is the omega-6 to omega-3 balance. A high omega-6 total paired with a low omega-3 total gives an elevated omega-6/omega-3 ratio, which favours a pro-inflammatory eicosanoid environment. For AAS users, whose cardiovascular and inflammatory status is already under pressure, keeping that ratio in check by raising EPA/DHA (rather than aggressively cutting essential omega-6s) is the sensible approach. Values are matrix and method dependent.

The ratio of arachidonic acid (omega-6) to EPA (omega-3) in the fatty-acid profile. It summarises the balance between pro-inflammatory and anti-inflammatory eicosanoid precursors, with a lower ratio reflecting a more favourable, less inflammatory balance.

PED: The AA/EPA ratio is arguably the most practically useful single number on an omega fatty-acid panel, because it captures the inflammatory balance in one figure. A high ratio (lots of arachidonic acid, little EPA) indicates a pro-inflammatory state; a lower ratio indicates that omega-3 intake is adequate to offset omega-6. It responds quickly and predictably to fish-oil supplementation, dropping as EPA rises, which makes it a good way to confirm an omega-3 protocol is working. For AAS users this is a cheap, modifiable lever that supports cardiovascular and general inflammatory health without any downside to the physique. Lower is generally better; values are matrix and method dependent.

The ratio of total omega-6 to total omega-3 fatty acids in the profile. It captures the overall dietary fatty-acid balance; a lower ratio reflects a more anti-inflammatory pattern closer to ancestral diets, while typical Western diets sit much higher.

PED: Where the AA/EPA ratio focuses on the specific inflammatory eicosanoid precursors, the omega-6/omega-3 ratio is the broader dietary-balance version. Ancestral intakes were near 1:1 to 4:1, whereas modern Western diets often run 15:1 or higher, a shift linked to greater inflammatory tone. Lowering the ratio is achieved mainly by adding EPA/DHA and moderating industrial omega-6 intake, not by removing essential omega-6 fats. For enhanced athletes this is a straightforward, evidence-based way to support cardiovascular and inflammatory health alongside the harder lipid work. Lower is generally better; values are matrix and method dependent.

The combined percentage of the marine omega-3 fatty acids EPA, DPA, and DHA in red blood cells, essentially the Omega-3 Index. It is the best-validated single measure of long-term marine omega-3 status and a recognised cardiovascular risk marker.

PED: This is the marker that matters most on an omega panel. The Omega-3 Index (red-cell EPA+DHA, often reported with DPA added) has robust outcome data: below about 4% is a high-risk zone for death from coronary heart disease, and 8% or above is the low-risk, cardioprotective target. It reflects months of intake, not the last meal, so it is a stable measure of habitual status. For AAS users, whose cardiovascular risk is elevated by adverse lipid changes, blood-pressure rises, and erythrocytosis, getting the Omega-3 Index into the 8%+ range is one of the clearest, cheapest, evidence-based protective moves available. It rises steadily with EPA/DHA intake, so it is easy to act on and re-measure. Values are matrix and method dependent, but the index is specifically standardised to red cells.

The concentration of medium-sized LDL particles measured by advanced lipoprotein testing (NMR or ion mobility). It is a subfraction of the total LDL particle number, intermediate in size and atherogenicity between large buoyant and small dense LDL.

PED: Medium LDL particles sit between the large, more buoyant LDL and the small, dense, most atherogenic LDL. They contribute to the total atherogenic particle burden (better captured by ApoB and LDL-P), and the clinically important question is usually the shift toward small dense particles rather than the medium fraction alone. AAS, especially oral 17-alpha-alkylated compounds, raise LDL particle number and drive the profile toward smaller, denser particles, so medium and small LDL often rise together on cycle while HDL is suppressed. Interpret this fraction as part of the whole subfraction pattern alongside ApoB, LDL-P, and small LDL. Reference ranges for individual subfractions are strongly method and lab dependent (NMR LipoProfile, ion mobility, and Boston Heart report differently), so trend against the same assay.

The concentration of small, dense LDL particles measured by advanced lipoprotein testing (NMR or ion mobility). Small dense LDL is the most atherogenic LDL subclass: these particles penetrate the arterial wall more readily, are more prone to oxidation, and persist longer in circulation.

PED: Small dense LDL (sdLDL) is the LDL subfraction most strongly tied to cardiovascular risk, over and above total LDL cholesterol. This is a genuine and important harm-reduction marker for enhanced athletes: AAS suppress HDL and shift LDL toward the small, dense phenotype, and oral 17-alpha-alkylated compounds (stanozolol, oxandrolone) and trenbolone are especially bad for it. Insulin resistance from GH/insulin use and high triglycerides push LDL even smaller. So a lean, apparently healthy bodybuilder can show a relatively modest LDL-C while carrying a highly atherogenic small dense LDL burden, which is exactly the discordance advanced lipoprotein testing exists to catch. Read it with ApoB, LDL-P, triglycerides, and HDL. Reference ranges for subfractions are strongly method and lab dependent (NMR LipoProfile, ion mobility, Boston Heart differ), so trend against the same assay rather than a universal cut-off.

Oxygen-carrying protein in red blood cells.

PED: AAS stimulate erythropoiesis (red blood cell production), increasing haemoglobin. This is a significant cardiovascular risk as high haemoglobin increases blood viscosity, raising stroke and heart attack risk. Values >180 g/L are concerning and warrant immediate intervention. EQ (Boldenone) is particularly notorious for raising haemoglobin.

Percentage of blood volume occupied by red blood cells.

PED: Directly related to haemoglobin. AAS increase haematocrit. Values >0.52 increase stroke and cardiovascular risk significantly. EQ (Boldenone) is particularly notorious for raising haematocrit.

Number of red blood cells per liter of blood.

PED: Increased by AAS-stimulated erythropoiesis. Follows haemoglobin and haematocrit trends.

Number of white blood cells. Important for immune function.

PED: Not typically significantly affected by AAS. Intense training can temporarily elevate. Low values may indicate overtraining or immune suppression.

Cell fragments essential for blood clotting.

PED: Generally not significantly affected by AAS. Monitor if using compounds that affect clotting or if taking aspirin/NSAIDs regularly.

Average size of red blood cells. Helps classify types of anemia.

PED: Not typically affected by AAS. Low MCV with low iron suggests iron deficiency from blood donations.

Average amount of haemoglobin per red blood cell.

PED: Not typically affected by AAS. Low MCH with low MCV suggests iron deficiency, common in athletes who donate blood regularly to manage high haematocrit.

Average concentration of haemoglobin in red blood cells.

PED: Not typically affected by AAS. Low MCHC can indicate iron deficiency. Useful alongside MCH and MCV to classify anaemia type.

Measures variation in red blood cell size. Elevated in mixed deficiency states.

PED: Can be elevated when iron is depleted from regular blood donations while AAS are stimulating new red blood cell production. A high RDW with normal MCV may indicate early iron deficiency.

Most abundant white blood cell type. First responders to bacterial infection.

PED: Can be transiently elevated after intense training. Chronic elevation may indicate infection or inflammation. Not typically directly affected by AAS.

White blood cells important for adaptive immunity (B cells, T cells, NK cells).

PED: Can be suppressed by overtraining or extreme caloric restriction during contest prep. Chronic low lymphocytes may indicate immune suppression.

White blood cells that differentiate into macrophages. Part of innate immunity.

PED: Not typically significantly affected by AAS. May be elevated with chronic inflammation or infection.

White blood cells involved in allergic responses and parasitic infections.

PED: Not typically affected by AAS. Elevation may indicate allergic reaction, parasitic infection, or certain medications.

Rarest white blood cell type. Involved in allergic and inflammatory responses.

PED: Not typically affected by AAS. Usually present in very small numbers. Rarely clinically significant in isolation.

Average size of platelets. Larger platelets are younger and more reactive. Can indicate bone marrow activity.

PED: Not directly affected by AAS. May increase when platelet turnover is high (e.g. from heavy training-induced microtrauma). Persistently elevated MPV with low platelets warrants investigation.

Immature red blood cells released from bone marrow. The absolute count is the most reliable indicator of bone marrow erythropoietic activity.

PED: AAS stimulate erythropoiesis via increased EPO production, suppressed hepcidin, and direct bone marrow stimulation — reticulocyte counts are typically elevated on cycle. Boldenone (EQ) has particularly marked erythropoietic effects. After blood donation (common for managing high haematocrit), reticulocytes spike within 3-6 days and normalise by 9-12 days. EPO use produces dramatic elevations — counts doubling from baseline is characteristic.

Percentage of immature granulocytes (metamyelocytes, myelocytes, promyelocytes) in peripheral blood. Normally near zero; elevation indicates bone marrow stimulation or infection.

PED: AAS stimulate granulopoiesis — stanozolol has been shown to accelerate neutrophil precursor maturation in bone marrow. EPO use stimulates broad haematopoiesis including granulocyte production. Intense training itself can cause transient elevation via exercise-induced bone marrow stimulation. Mild elevation (0.5-2%) is common in enhanced athletes and usually benign. Values >3% warrant investigation for infection or bone marrow pathology regardless of PED use.

Red blood cell precursors normally confined to bone marrow. Their presence in peripheral blood indicates severe erythropoietic stress, bone marrow pathology, or extramedullary haematopoiesis.

PED: EPO use and AAS-driven erythropoiesis can push NRBCs into peripheral blood, especially at high doses. High-dose testosterone, trenbolone, and equipoise (boldenone) are strongly erythropoietic. NRBCs are rare even in enhanced athletes — their presence at >1/100 WBC is always clinically significant and warrants investigation. Combined AAS + EPO use increases risk. Severe polycythaemia (HCT >54%) can be accompanied by NRBCs.

Absolute count of nucleated red blood cells per microlitre of blood. Reported on modern automated haematology analysers alongside the relative count (per 100 WBCs). Any value above 0 indicates erythropoietic stress, bone marrow pathology, or extramedullary haematopoiesis.

PED: Same clinical entity as NRBC per 100 WBCs but expressed as an absolute concentration. The Sysmex XN, Beckman DxH, and Abbott Alinity haematology platforms now report this alongside the relative NRBC count. In enhanced athletes, the most common driver is aggressive erythropoietic stimulation: high-dose testosterone, trenbolone, equipoise, and exogenous EPO can push nucleated RBCs into peripheral circulation. Combined AAS plus EPO use is the highest-risk pattern. Severe polycythaemia (HCT above 54%) increases the likelihood of detectable absolute NRBC. Any value above 0.01 K/uL warrants attention and a full erythropoietic panel (haemoglobin, haematocrit, reticulocyte count). Persistent elevation without obvious PED cause requires haematology referral and bone marrow evaluation.

The proportion of white blood cells that are neutrophils, expressed as a percentage of the total. This is the relative differential value, distinct from the absolute neutrophil count. Because it is a proportion, it shifts whenever any other white-cell line rises or falls, so it is best interpreted alongside the absolute count.

PED: A relative value, so read it together with the absolute neutrophil count and the rest of the differential. Intense training transiently raises the neutrophil percentage (a demargination/stress response), which normalises within a day; always use a rested draw. It is not directly altered by AAS, though the neutrophil-to-lymphocyte relationship is sometimes used as a rough systemic-inflammation gauge in athletes.

The absolute neutrophil count divided by the absolute lymphocyte count. It is a simple, inexpensive index of systemic inflammation and physiological stress derived from a standard full blood count. A higher ratio reflects a shift toward innate (neutrophil) immunity and away from lymphocytes, a pattern seen with inflammation, infection, and stress.

PED: A useful low-cost gauge of systemic inflammation and training stress in athletes, best read as a trend rather than a single value. Hard training, overtraining, and acute physical or psychological stress raise the ratio through a cortisol-driven neutrophilia plus lymphopenia; it typically normalises within a day of rest, so use a rested, non-post-workout draw. It is not directly altered by AAS, but a persistently elevated NLR in an enhanced athlete can flag chronic inflammation or under-recovery worth investigating alongside CRP. Values are only meaningful when both the neutrophil and lymphocyte counts are themselves valid, so always interpret it with the full differential.

The proportion of white blood cells that are lymphocytes, expressed as a percentage of the total. This relative differential value is distinct from the absolute lymphocyte count and shifts with changes in any other white-cell line, so it should be interpreted alongside the absolute count.

PED: A relative value best read with the absolute lymphocyte count. In athletes, a low lymphocyte percentage can accompany the acute post-exercise state or, if persistent alongside a low absolute count, may signal overtraining, severe contest-prep caloric deficit, or chronic stress. A high percentage is most often a relative rise during viral infection. Not directly changed by AAS.

The proportion of white blood cells that are monocytes, expressed as a percentage of the total. This relative differential value is distinct from the absolute monocyte count and is best interpreted alongside it, since it shifts with changes in other white-cell lines.

PED: A relative value, rarely actionable in isolation. Mild elevation of the monocyte percentage can accompany recovery from infection or chronic low-grade inflammation, which in athletes may reflect ongoing musculoskeletal inflammation or overuse. Not directly affected by AAS. Interpret alongside the absolute count and inflammatory markers such as CRP.

The proportion of white blood cells that are eosinophils, expressed as a percentage of the total. This relative differential value is distinct from the absolute eosinophil count and should be interpreted alongside it.

PED: A relative value most useful when read with the absolute eosinophil count. Elevated eosinophil percentage most often reflects allergy or atopy, and sometimes parasitic infection or a drug/supplement reaction. Not directly affected by AAS, though new supplements and injectable excipients can occasionally trigger a reaction. Interpret alongside the absolute count and clinical history.

The proportion of white blood cells that are basophils, expressed as a percentage of the total. Basophils are the rarest white-cell type, so this value is normally very low. It is the relative differential value, distinct from the absolute basophil count.

PED: The rarest white-cell line and rarely significant in isolation. A mildly raised basophil percentage is almost never meaningful on its own; persistent elevation can occasionally accompany allergic conditions, hypothyroidism, or, rarely, myeloproliferative disorders. Not affected by AAS. Interpret within the full differential.

A measure of the variability in platelet size (the width of the platelet size distribution). A higher PDW means platelets vary more in size, which reflects differences in platelet production and turnover. It is reported automatically as part of the platelet indices on a full blood count.

PED: A minor platelet index, most useful read alongside platelet count and mean platelet volume (MPV) rather than alone. A raised PDW indicates a more heterogeneous, often more active platelet population and tends to move with MPV. It is not directly affected by AAS, but because enhanced athletes carry elevated cardiovascular risk (erythrocytosis, blood pressure, lipid shifts), platelet indices are occasionally noted as part of the broader thrombotic-risk picture. On its own it is rarely actionable.

The fraction of blood volume occupied by platelets, analogous to the haematocrit for red cells. It is calculated from the platelet count and mean platelet volume and reflects total platelet mass. It is reported as one of the platelet indices on a full blood count.

PED: A minor platelet index that summarises total platelet mass, best interpreted with the platelet count and MPV. Note the common source-PDF mislabel: some labs print plateletcrit under a 'PCT' abbreviation, and it can be confused with platelet distribution width, but the percentage unit identifies it as plateletcrit. Not directly affected by AAS; occasionally relevant to the broader thrombotic-risk picture in enhanced athletes with erythrocytosis or hypertension, but rarely actionable in isolation.

Measures the time for blood to clot via the intrinsic and common coagulation pathways. Used to screen for clotting factor deficiencies and to monitor unfractionated heparin therapy.

PED: APTT itself is not a routine PED monitoring test, but coagulation matters for enhanced athletes. Androgens (testosterone and other AAS) drive erythropoiesis, and the resulting rise in haematocrit thickens the blood and raises thrombotic risk independent of any clotting-time change. AAS also shift the haemostatic balance toward a prothrombotic state (altered fibrinolysis, platelet activation, and changes in clotting factor and antithrombin levels), so a normal APTT does NOT mean clot risk is low if haematocrit is high. APTT is the standard test used to monitor unfractionated heparin if anticoagulation is ever required. No PED shifts the healthy target range, so the bodybuilder reference range equals the standard range.

Measures the time for blood to clot via the extrinsic and common coagulation pathways. Sensitive to clotting factors I, II, V, VII and X, and used to assess liver synthetic function and vitamin K status.

PED: PT is not a routine PED test, but it is a useful window on liver synthetic function, which matters for users of oral 17-alpha-alkylated AAS. The liver makes most clotting factors, so significant AAS-induced hepatotoxicity can prolong PT. Separately, androgen-driven erythrocytosis raises thrombotic risk through elevated haematocrit rather than through PT, so a normal PT does not exclude clot risk in a polycythaemic athlete. PT (as the INR) is the standard test to monitor warfarin. No PED shifts the healthy target, so the bodybuilder range equals the standard range.

A standardised expression of the prothrombin time that corrects for differences between laboratory reagents. Used mainly to monitor warfarin (vitamin K antagonist) therapy and to assess liver synthetic function.

PED: INR is not a PED marker, but it is the standard way to report prothrombin time and to gauge liver synthetic capacity, which is relevant for oral 17-alpha-alkylated AAS users. A rising INR off anticoagulation can signal impaired hepatic clotting factor synthesis. Note the direction of risk: androgen use raises clotting risk (through elevated haematocrit and a prothrombotic shift), whereas a HIGH INR reflects slower clotting and bleeding risk, so the two are not opposites of the same axis. No PED shifts the healthy target; the bodybuilder range equals the standard range.

Measures the time for fibrinogen to convert to fibrin after thrombin is added, isolating the final step of clot formation. Sensitive to fibrinogen level and function and to thrombin inhibitors such as heparin and direct thrombin inhibitors.

PED: Thrombin clotting time (also called thrombin time) is a specialised coagulation test, not a routine PED marker. It is prolonged by low or dysfunctional fibrinogen and by anticoagulants that inhibit thrombin (heparin, dabigatran). For enhanced athletes, the more important coagulation issue is androgen-driven erythrocytosis raising haematocrit and clot risk, which the TCT does not measure. No PED shifts the healthy target, so the bodybuilder range equals the standard range.

A fibrin degradation product released when a blood clot is broken down. Used to help rule out venous thromboembolism (deep vein thrombosis and pulmonary embolism) and to assess disseminated intravascular coagulation.

PED: D-dimer is highly relevant to enhanced athletes because AAS increase thrombotic risk: androgen-driven erythrocytosis raises haematocrit and blood viscosity, and AAS shift haemostasis toward clotting and impaired fibrinolysis. A raised D-dimer signals active clot formation and breakdown somewhere in the body, so in a polycythaemic user with leg swelling, chest pain, or breathlessness it is an urgent finding. D-dimer is most useful for its negative predictive value: a normal result makes clinically significant clot very unlikely. It is non-specific and rises with inflammation, hard training, injury, and recent surgery. No PED lowers the healthy target, so the bodybuilder range equals the standard range.

A clotting protein made by the liver that thrombin converts to fibrin, the structural mesh of a blood clot. It is also an acute-phase reactant and an independent cardiovascular risk marker.

PED: Fibrinogen matters for enhanced athletes on two fronts. First, it is a clotting factor, so higher levels contribute to a more prothrombotic state, compounding the clot risk from androgen-driven erythrocytosis and high haematocrit. Second, it is an acute-phase protein that rises with inflammation, so heavy training, high body fat, and the low-grade inflammation seen on some cycles can push it up. A persistently high fibrinogen is an independent cardiovascular risk factor, which is directly relevant to the cardiovascular focus of harm reduction in PED users. No PED shifts the healthy target, so the bodybuilder range equals the standard range.

Amount of iron circulating in the blood.

PED: AAS-driven increased red blood cell production increases iron demand. Regular blood donors (recommended for high haematocrit) may develop iron deficiency. Monitor iron studies regularly if donating blood.

Protein that stores iron. Low levels indicate depleted iron stores.

PED: Regular blood donation (recommended for AAS users with high haematocrit) depletes ferritin. Also an acute phase reactant so can be falsely elevated with inflammation. Optimal for athletes: 50-150 ug/L.

Protein that transports iron in the blood.

PED: Rises when iron stores are depleted. Good indicator of iron status alongside ferritin.

Percentage of transferrin bound with iron. Indicates iron availability.

PED: Low saturation with low ferritin confirms iron deficiency. Monitor in regular blood donors.

Measures the maximum capacity of transferrin to bind iron. Elevated in iron deficiency, reduced in iron overload or chronic inflammation.

PED: AAS-driven erythropoiesis plus regular blood donation creates high iron throughput. Each donation removes ~250mg of iron. The liver responds by producing more transferrin, raising TIBC. Interpret alongside ferritin, serum iron, and transferrin saturation — high TIBC + low ferritin + low TSAT confirms true iron deficiency (most common from donation). Low TIBC + high ferritin + low iron suggests anemia of chronic disease or inflammation (ferritin falsely elevated).

Reflects total erythropoietic activity and cellular iron demand. Unlike ferritin, it is NOT affected by inflammation, making it the most reliable iron marker in inflammatory states.

PED: The most valuable iron marker for AAS users because unlike ferritin, it is NOT an acute phase reactant — unaffected by inflammation, liver stress from oral AAS, or intense training. When ferritin appears normal but the athlete has iron deficiency symptoms (fatigue, poor recovery), sTfR reveals whether tissue iron demand is being met. The sTfR/log ferritin index (sTfR ÷ log10 ferritin) >1.8 indicates iron-deficient erythropoiesis — this should be the gold standard for AAS users who donate blood regularly.

The reserve iron-binding capacity of transferrin: the portion not currently carrying iron. UIBC plus serum iron equals the total iron binding capacity (TIBC). It rises in iron deficiency and falls in iron overload or inflammation.

PED: UIBC is directly tied to the iron paradox on TRT and AAS. Testosterone and other androgens stimulate erythropoiesis, and the surge in red-cell production consumes iron stores, so a bodybuilder can be building red cells (high haemoglobin and haematocrit) while running low on iron. As iron stores fall, the body upregulates transferrin, so UIBC (and TIBC) rise while serum iron and ferritin drop. Regular blood donation to manage high haematocrit accelerates this, each donation removing roughly 250mg of iron. Read UIBC together with ferritin, serum iron, and transferrin saturation rather than alone. No PED sets a different healthy target, so the bodybuilder range equals the standard range.

Pituitary hormone that controls thyroid gland output.

PED: T3 supplementation (cytomel, common in contest prep) will suppress TSH. Prolonged suppression can take weeks to recover. Trenbolone may affect thyroid function in some individuals.

Active thyroid hormone. Controls metabolic rate.

PED: May be affected by severe caloric restriction during contest prep. T3 supplementation reduces T4 production through feedback. Important to check alongside TSH.

Most active thyroid hormone. Directly affects metabolic rate.

PED: Exogenous T3 use will show elevated Free T3 with suppressed TSH and T4. Contest prep caloric restriction naturally lowers T3 (metabolic adaptation). GH can improve T4-to-T3 conversion.

An inactive isomer of T3 produced when the body converts T4 down the alternative deiodination pathway. Reverse T3 has no thyroid-hormone activity but competes with active T3 at the cellular level. It rises when the body deliberately downregulates metabolism, so it is used as a marker of non-thyroidal illness and metabolic stress rather than of primary thyroid disease.

PED: Directly relevant to hard-dieting and contest-prep athletes. Aggressive caloric restriction, very low body fat, overtraining, illness, and high cortisol all shift T4 conversion away from active T3 and toward reverse T3, the classic euthyroid sick syndrome (low T3 syndrome) picture: normal or low-normal TSH, low Free T3, and a raised rT3. This is an adaptive slowdown, not primary hypothyroidism, and it typically reverses with refeeding and recovery rather than with thyroid medication. Exogenous T4 can raise rT3 (more substrate for the inactive pathway), whereas exogenous T3 (Cytomel) bypasses conversion and tends to lower endogenous rT3. A high rT3 with low Free T3 in a lean, heavily-dieting athlete signals metabolic adaptation and the need to restore energy availability. The Free T3 to reverse T3 ratio is sometimes used to gauge tissue-level thyroid status.

Autoantibodies against thyroid peroxidase. Elevated levels are the hallmark of Hashimoto's thyroiditis (autoimmune hypothyroidism).

PED: AAS reduce thyroxine-binding globulin (TBG), causing total T3/T4 to appear low while free hormones remain unchanged — this is not autoimmune. GH increases T4-to-T3 conversion and can unmask latent thyroid insufficiency if anti-TPO is borderline. Exogenous T3 (Cytomel) suppresses TSH, which can mask rising anti-TPO. If symptoms like fatigue, weight gain, or poor recovery persist post-cycle, check anti-TPO alongside TSH and Free T4 to rule out Hashimoto's.

Autoantibodies against thyroglobulin, a protein produced by the thyroid gland. Elevated levels indicate autoimmune thyroid disease, most commonly Hashimoto's thyroiditis. Also used in thyroid cancer monitoring, where TgAb interferes with thyroglobulin tumour marker assays.

PED: AAS are broadly immunosuppressive and may suppress autoantibody production, so TgAb may appear deceptively low on-cycle. Check during off-cycle or cruise periods for a more accurate reading. GH increases T4-to-T3 conversion and may unmask latent autoimmune thyroiditis in susceptible individuals. Exogenous T3 (Cytomel) profoundly suppresses TSH, which can mask a developing autoimmune process. After T3 discontinuation, TSH rebound can amplify the autoimmune response and temporarily spike TgAb.

An antibody that binds the TSH receptor and switches it on, driving the thyroid to overproduce hormone independently of TSH. The specific cause of Graves' disease.

PED: This is the test that names the cause when thyroid function is genuinely overactive. That matters here because the picture it produces can be mistaken for something self-inflicted: suppressed TSH with raised free T4 and free T3 looks superficially like exogenous thyroid hormone use, and someone running T3 or T4 who develops Graves' can have it written off as their own dosing. The distinction is straightforward on paper. Exogenous T3 suppresses TSH while thyroglobulin falls and antibodies are absent; Graves' suppresses TSH with positive TSI and usually a diffusely enlarged gland. Do not interpret this while running thyroid medication without telling the clinician, because the two states are easy to confuse and the treatments are opposite. Also note that raised TSI in pregnancy crosses the placenta and can affect the fetal thyroid, so it carries weight beyond the person tested.

The total amount of thyroxine (T4) in serum, including both the small free (active) fraction and the large fraction bound to carrier proteins such as thyroxine-binding globulin (TBG), transthyretin, and albumin. Because it measures bound plus free hormone, Total T4 moves whenever binding-protein levels change, unlike Free T4 which reflects only the unbound hormone.

PED: Total T4 is heavily influenced by binding proteins, so it can shift without any true change in thyroid status. Oral oestrogens (and the altered hepatic protein synthesis seen with some AAS use) raise TBG and push Total T4 up, while high-dose androgens can lower TBG and Total T4, in both cases with normal Free T4 and normal thyroid function. Pregnancy raises it too. For monitoring thyroid status on cycle, TSH plus Free T4 (or Free T3) are more reliable than Total T4. Total T4 is mainly useful as part of the legacy Total T4 x T3 Uptake calculation (the Free T4 Index) when a direct Free T4 is unavailable.

An indirect, legacy measure of how saturated the thyroid-binding proteins are with hormone, also reported as the Thyroid Hormone Binding Ratio (THBR). It does NOT measure T3 levels directly; it moves inversely to the number of unoccupied binding sites on thyroxine-binding globulin. It is used together with Total T4 to calculate the Free T4 Index and correct for binding-protein variation.

PED: T3 Uptake is a binding-protein test, not a thyroid-activity test. When TBG rises (oral oestrogen, pregnancy, some AAS-related hepatic effects) there are more free binding sites, so T3 Uptake falls; when TBG falls (high-dose androgens, nephrotic states) T3 Uptake rises. Read alongside Total T4: a high Total T4 with a low T3 Uptake suggests raised binding proteins rather than hyperthyroidism, whereas both moving in the same direction suggests a true thyroid change. Most modern panels replace this with a direct Free T4, so treat it mainly as an input to the Free T4 Index.

A calculated estimate of free thyroid hormone, historically called T7, derived by multiplying Total T4 by the T3 Uptake fraction. By combining a total hormone level with a binding-protein measure, it corrects for changes in binding proteins and approximates what a direct Free T4 assay measures. It is a legacy calculation from the era before reliable direct Free T4 tests.

PED: The Free T4 Index exists to strip out binding-protein noise: if Total T4 is high only because oestrogen or AAS-related changes raised TBG, the accompanying low T3 Uptake pulls the index back into the normal range, correctly indicating normal thyroid status. This makes it more informative than Total T4 alone in athletes whose binding proteins are shifted by oral oestrogens or high-dose androgens. That said, the modern direct Free T4 assay already in this knowledge base is the preferred test; the index is mainly seen on older or budget panels. Reference ranges are strongly method-dependent, so compare against the reporting lab's own range.

Essential trace mineral and cofactor for hundreds of enzymes. Required for testosterone synthesis, immune function, wound healing, protein synthesis, and antioxidant defence.

PED: Highly relevant to athletes. Zinc deficiency lowers testosterone and impairs recovery and immunity, which is why zinc (often as ZMA) is one of the most commonly supplemented minerals in bodybuilding. The flip side matters more than most realise: chronic high-dose zinc supplementation is the leading cause of copper deficiency, which can cause anaemia and low white cells. Zinc and copper compete for absorption, so they should always be interpreted together. Note that serum zinc is an imperfect status marker: it falls with inflammation (it is a negative acute phase reactant), tracks albumin, and is affected by recent meals and time of day, so a single low value is not definitive.

Essential trace mineral and cofactor for ceruloplasmin, iron metabolism, connective tissue cross-linking, energy production, and antioxidant enzymes. Most circulating copper is carried bound to ceruloplasmin.

PED: The mineral most often overlooked in enhanced athletes. The single most common cause of low copper in this population is chronic high-dose zinc supplementation, which blocks copper absorption and can produce anaemia and low neutrophils that mimic a bone marrow disorder. Copper peptides such as GHK-Cu and the GLOW blend are popular for skin and connective tissue, adding to copper interest. On the other side, estrogen raises serum copper: women and anyone with high aromatisation on cycle, or those using estrogenic compounds, will tend to run higher copper because estrogen increases ceruloplasmin synthesis in the liver. Always interpret copper with zinc and, where available, ceruloplasmin.

Essential electrolyte for fluid balance, nerve and muscle function.

PED: Water manipulation during contest prep can affect sodium levels. Generally stable on AAS. Stay hydrated and maintain electrolyte balance.

Essential electrolyte for heart function and muscle contraction.

PED: Diuretic use during contest prep can dangerously deplete potassium. Critical for heart function -- low potassium can cause fatal cardiac arrhythmias. Monitor closely if using diuretics.

Electrolyte that helps maintain fluid balance and acid-base status.

PED: Generally stable on AAS. Can be affected by dehydration or excessive fluid intake. Follows sodium trends in most cases.

Key buffer in the blood that maintains acid-base balance. Low levels indicate metabolic acidosis.

PED: Can be affected by intense exercise (lactic acidosis lowers bicarbonate transiently). Generally not affected by AAS. Low values with high anion gap may indicate kidney issues.

Calculated value (Na - Cl - HCO3) that helps identify causes of metabolic acidosis.

PED: Can be transiently elevated after intense training due to lactic acid accumulation. Persistent elevation warrants investigation. Not directly affected by AAS.

Essential mineral for bones, muscles, and nerve function.

PED: Generally stable on AAS. Adequate vitamin D and calcium intake important for bone health and muscle function.

Calcium level adjusted for albumin concentration. More accurate than total calcium when albumin is abnormal. Formula: Corrected Ca = Total Ca + 0.02 × (40 - Albumin).

PED: More clinically meaningful than uncorrected calcium when albumin is low (e.g., during illness or liver stress from oral AAS). If total calcium appears normal but albumin is low, corrected calcium may reveal true hypercalcemia. Generally stable on AAS.

Essential mineral involved in hundreds of enzymatic reactions.

PED: Many athletes are deficient despite adequate diet. Important for recovery, sleep, muscle function, and over 300 biochemical reactions. Heavy sweating depletes magnesium.

Mineral important for energy production and bone health.

PED: Generally not significantly affected by AAS or training. Part of the ATP energy system.

Non-specific marker of inflammation. Elevated in infection, injury, or chronic disease.

PED: Training-induced inflammation can elevate CRP. Some AAS may increase systemic inflammation. High-sensitivity CRP (hs-CRP) is more useful for cardiovascular risk assessment -- target <1.0 mg/L for low cardiovascular risk. Rest 48-72h before blood draw for accurate baseline.

Non-specific marker of inflammation that measures how quickly red blood cells settle in a tube. Elevated in infection, autoimmune conditions, and chronic inflammation. Slower to rise and fall than CRP.

PED: Complementary to CRP — ESR rises more slowly but stays elevated longer, making it useful for detecting chronic/ongoing inflammation. AAS-induced polycythemia (high RBC/haematocrit) can actually lower ESR because more packed red cells settle slower. If ESR is elevated despite high haematocrit, it suggests significant inflammation. Not typically a primary monitoring marker for PED users, but useful alongside CRP for a complete inflammatory picture.

Amino acid in the blood. Elevated levels are an independent risk factor for cardiovascular disease, stroke, blood clots, and cognitive decline. Metabolised by B-vitamins (B6, B12, Folate).

PED: An often-overlooked cardiovascular risk marker for PED users. Elevated homocysteine damages blood vessel walls and promotes clotting -- compounding the cardiovascular risk from AAS-worsened lipids and elevated haematocrit. Some AAS may affect homocysteine metabolism. Target <10 umol/L for optimal cardiovascular protection.

NMR-derived composite inflammatory biomarker reflecting glycosylation of acute phase proteins. More stable than CRP with lower intra-individual variability, providing a better measure of chronic systemic inflammation.

PED: Chronic PED use causes sustained low-grade systemic inflammation reflected by GlycA. Unlike CRP which spikes acutely and normalises quickly, GlycA captures chronic inflammatory burden — more relevant for long-term health monitoring in enhanced athletes. AAS-induced hepatic acute phase protein production elevates GlycA. Intense training, joint stress, and chronic muscle damage from heavy lifting contribute. GH may reduce GlycA through anti-inflammatory effects, partially counteracting AAS-driven elevation. GlycA independently predicts cardiovascular events and all-cause mortality.

An autoantibody (usually IgM) directed against the Fc portion of the body's own IgG. It is used mainly as a screening and classification aid for rheumatoid arthritis, but it is far from specific and can be raised in many other conditions.

PED: Rheumatoid Factor has low specificity, so a positive result is not a diagnosis. It is elevated in rheumatoid arthritis but also in other autoimmune diseases (Sjogren's, lupus), chronic infections (hepatitis C, endocarditis), and simply with older age, and a meaningful minority of healthy people carry a low-titre positive with no disease. For an athlete with genuine inflammatory joint pain, morning stiffness, and swelling, RF is worth checking alongside anti-CCP (a more specific test), CRP, and ESR. In isolation, and especially at low titre, it is weak evidence and should not trigger alarm. Heavy training soreness and mechanical joint pain are not causes of a raised RF.

An antibody directed against citrullinated proteins that is highly specific for rheumatoid arthritis and often appears years before symptoms. Positivity supports the diagnosis and predicts a more erosive disease course.

PED: Anti-CCP is not affected by AAS, GH, or peptides, but it is worth understanding for lifters. Enhanced athletes frequently have aches, joint pain, and stiffness from heavy training, prior injuries, and osteoarthritis, and it is easy to dismiss genuine inflammatory arthritis as normal gym wear and tear. A positive anti-CCP points to rheumatoid arthritis rather than mechanical joint pain and warrants rheumatology review. Units and cutoffs are strongly assay-dependent, so always read the result against the reporting laboratory's own reference interval. The bodybuilder range equals the standard range.

An autoantibody against double-stranded DNA that is highly specific for systemic lupus erythematosus (SLE). Rising titres often track disease activity, particularly lupus nephritis.

PED: Anti-dsDNA is not affected by AAS, GH, or peptides. It is relevant to enhanced athletes mainly as a confounder: fatigue, joint pain, rashes, and abnormal routine bloodwork can be blamed on cycles or training when an underlying autoimmune disease is present. Anti-dsDNA helps confirm SLE and, because titres can mirror disease activity, is used to monitor flares. Assays and cutoffs vary (ELISA, Farr, immunofluorescence), so interpret against the reporting laboratory's reference interval. The bodybuilder range equals the standard range.

An antiphospholipid antibody targeting beta-2 glycoprotein I. It is one of the laboratory criteria for antiphospholipid syndrome, an autoimmune clotting disorder that causes venous and arterial thrombosis and pregnancy loss.

PED: Anti-B2 glycoprotein I is not affected by AAS, GH, or peptides, but the condition it flags, antiphospholipid syndrome, is directly relevant to enhanced athletes because it compounds thrombotic risk. AAS already raise clot risk through erythrocytosis (high haematocrit) and a prothrombotic haemostatic shift; a positive antiphospholipid antibody adds an independent, powerful clotting drive. Anyone with an unexplained clot, especially a younger lifter, should be evaluated for antiphospholipid syndrome. Criteria require persistent positivity confirmed on repeat testing at least 12 weeks apart. Interpret against the laboratory's own cutoff. The bodybuilder range equals the standard range.

An antiphospholipid antibody directed against cardiolipin. Together with anti-B2 glycoprotein I and lupus anticoagulant, it forms the laboratory criteria for antiphospholipid syndrome, a cause of thrombosis and pregnancy loss.

PED: Anticardiolipin IgG is not affected by AAS, GH, or peptides, but the antiphospholipid syndrome it helps diagnose adds a strong, independent clotting drive on top of the thrombotic risk androgens already create through erythrocytosis and prothrombotic haemostatic changes. Moderate-to-high titre IgG carries more weight than low-level positivity. Criteria require persistent positivity confirmed at least 12 weeks apart, since transient positives occur with infections. Interpret against the laboratory's own cutoff. The bodybuilder range equals the standard range.

The IgM class of anticardiolipin antibody, part of the antiphospholipid antibody panel used in the diagnosis of antiphospholipid syndrome. IgM positivity is less specific than IgG and more often transient.

PED: Anticardiolipin IgM is not affected by AAS, GH, or peptides. Like the IgG class it flags antiphospholipid syndrome, a clotting disorder that compounds the thrombotic risk androgens create through erythrocytosis and prothrombotic haemostatic changes. IgM is more prone to transient positivity (infections, other conditions) and is generally considered less specific than IgG, so persistence and correlation with clinical events matter. Confirm on repeat testing at least 12 weeks apart and interpret against the laboratory's own cutoff. The bodybuilder range equals the standard range.

A central protein of the complement system, part of innate immunity. Levels fall when complement is consumed by immune-complex disease (notably active lupus) and rise as a non-specific acute-phase reactant.

PED: Complement C3 is not affected by AAS, GH, or peptides. It matters for enhanced athletes mostly as part of an autoimmune work-up: a low C3, especially with a low C4 and positive anti-dsDNA, points to active systemic lupus, which can masquerade as training fatigue, joint pain, or unexplained abnormal bloodwork. As an acute-phase protein, C3 can also rise modestly with inflammation, infection, or heavy training, so a high value is far less specific than a low one. The clinically important direction is LOW (consumption). The bodybuilder range equals the standard range.

A protein of the classical complement pathway. Like C3 it is consumed in active immune-complex disease (especially lupus) and can rise modestly as an acute-phase reactant, but C4 often falls earlier and further than C3 in lupus flares.

PED: Complement C4 is not affected by AAS, GH, or peptides. It is used alongside C3 in autoimmune assessment: a low C4, particularly with a low C3 and positive anti-dsDNA, indicates active systemic lupus, which can be mistaken for the fatigue and joint pain of hard training. C4 is often the more sensitive of the two in lupus, sometimes dropping before C3. It can rise mildly as an acute-phase protein, so a high value is non-specific. The clinically important direction is LOW (consumption). The bodybuilder range equals the standard range.

A neutrophil-derived protein measured in stool that reflects inflammation of the gut lining. It is used to distinguish inflammatory bowel disease (Crohn's, ulcerative colitis) from non-inflammatory conditions such as irritable bowel syndrome, and to monitor disease activity.

PED: Faecal calprotectin is not affected by AAS, GH, or peptides directly, but gut symptoms are common in enhanced athletes and this test helps separate serious inflammation from benign causes. High-dose NSAID use for training aches can inflame the gut and raise calprotectin, and very high protein intakes, aggressive cutting diets, and some supplements can provoke GI symptoms. A normal calprotectin makes inflammatory bowel disease unlikely and points toward irritable bowel syndrome; a high result warrants proper gastroenterology work-up rather than self-treatment. The bodybuilder range equals the standard range.

An antibody against gliadin, a component of gluten, historically used to screen for coeliac disease. This is the older native (non-deamidated) gliadin assay, which is less sensitive and specific than deamidated gliadin peptide (DGP) IgG and tissue transglutaminase (tTG) IgA, now the preferred coeliac tests.

PED: Gliadin IgG is not affected by AAS, GH, or peptides. It is relevant to athletes because undiagnosed coeliac disease and gluten sensitivity can cause fatigue, poor recovery, bloating, and malabsorption of iron and other nutrients that then show up on routine bloodwork. Note that this older native gliadin antibody test has largely been superseded: current coeliac screening relies on tissue transglutaminase (tTG) IgA and deamidated gliadin peptide (DGP) IgG, and diagnosis requires the patient to be eating gluten at the time of testing. Treat a positive native gliadin IgG as a prompt for proper coeliac testing, not as a diagnosis. The bodybuilder range equals the standard range.

Fragment cleaved from proinsulin and released into the blood in equal (equimolar) amounts with endogenous insulin. Reflects how much insulin the pancreatic beta cells are actually producing and, unlike injected insulin, is not present in pharmaceutical insulin.

PED: Strong PED relevance. Because injected (exogenous) insulin contains no C-peptide, this test separates the body's own insulin output from injected insulin: a bodybuilder using exogenous insulin will show high blood insulin but low or suppressed C-peptide, whereas insulin resistance from GH or MK-677 drives high endogenous insulin AND high C-peptide. C-peptide is the better gauge of true beta-cell output and is more stable than insulin (longer half-life, no first-pass liver clearance). Use it alongside fasting insulin, glucose, and HOMA-IR when screening for the insulin resistance that accompanies growth hormone, MK-677, and high-calorie growth phases.

Blood sugar level. Elevated levels indicate diabetes risk.

PED: GH use can elevate fasting glucose and potentially cause insulin resistance. Important to monitor on GH, especially at higher doses. High carb diets can affect non-fasting values.

Average blood sugar over 2-3 months. Best marker for long-term glucose control.

PED: GH use can worsen HbA1c over time, indicating insulin resistance. More reliable than single glucose readings as it reflects 2-3 months average. High haematocrit from AAS can affect accuracy of some HbA1c assays. Target <5.5% for optimal metabolic health.

IFCC-standardised HbA1c measurement. Same marker as HbA1c % but in SI units. Normal: <42 mmol/mol. Pre-diabetes: 42-47. Diabetes: >=48. Conversion: mmol/mol = (% - 2.15) x 10.929.

PED: Equivalent to HbA1c % — same clinical significance. GH use can worsen HbA1c over time, indicating insulin resistance. High haematocrit from AAS can affect accuracy of some HbA1c assays. Australian labs report both units; mmol/mol is the IFCC standard.

Hormone that controls blood sugar. High levels indicate insulin resistance.

PED: GH use increases insulin resistance, requiring more insulin to control blood sugar. Some athletes use exogenous insulin (extremely dangerous -- can cause fatal hypoglycaemia). Low fasting insulin with normal glucose is optimal and indicates good insulin sensitivity.

Calculated index of insulin resistance derived from fasting glucose and fasting insulin. Lower values indicate better insulin sensitivity. The most practical tool for detecting early GH/peptide-induced metabolic dysfunction.

PED: Auto-calculated when both Fasting Glucose and Fasting Insulin are present in a blood test. Formula: (Glucose mmol/L x Insulin mIU/L) / 22.5. Lean, muscular athletes typically have lower baseline HOMA-IR (0.5-1.0) than sedentary adults. This means even 'normal' values (1.5-2.0) can represent a meaningful shift on GH or MK-677. Track the trend, not just the absolute number. A HOMA-IR that doubles from 0.8 to 1.6 over a GH cycle is a stronger signal than a single reading of 1.6 in isolation. GH, MK-677, and other GH-releasing peptides are the primary drivers of HOMA-IR elevation in this population. The index catches insulin resistance weeks before fasting glucose alone would flag a problem.

A measure of glycated serum proteins (chiefly glycated albumin) that reflects average blood glucose over roughly the previous 2 to 3 weeks. Because serum proteins turn over faster than red blood cells, it captures a shorter, more recent window than HbA1c.

PED: Fructosamine is most useful precisely when HbA1c is unreliable, which is a real and under-appreciated issue for enhanced athletes. HbA1c depends on red-cell lifespan, so AAS/TRT-driven erythrocytosis, frequent therapeutic phlebotomy or blood donation, and any recent blood loss all shorten red-cell survival and falsely LOWER HbA1c, potentially masking real hyperglycaemia. In those situations fructosamine (or glycated albumin) gives a truer picture of glucose control. This matters for athletes running growth hormone, MK-677, or exogenous insulin, all of which can push glucose up: a reassuring HbA1c in a polycythaemic GH user may be misleading, and a fructosamine cross-check is worthwhile. It also responds faster, so it shows the effect of a diet or drug change within a few weeks rather than months. Note that low albumin or high protein turnover can distort the result.

Average blood glucose over the preceding 2-3 months, calculated directly from HbA1c. Expresses long-term control in the same units as a finger-prick reading rather than as a percentage.

PED: Not an independent measurement. eAG is derived arithmetically from HbA1c (eAG in mmol/L = 1.59 x HbA1c% - 2.59), so it carries every limitation HbA1c has and adds none of its own information. That matters for enhanced athletes because AAS-driven erythrocytosis, frequent blood donation, and shortened red cell survival all falsely lower HbA1c and therefore falsely lower eAG. Growth hormone, MK-677, and high-dose insulin users can show a deceptively reassuring eAG while running genuinely high post-meal glucose. If insulin resistance is the question, fasting insulin, HOMA-IR, or a CGM will tell you far more than eAG will.

Total volume of ejaculate. Low volume may indicate obstruction, retrograde ejaculation, or hormonal insufficiency.

PED: AAS use suppresses gonadotropins (LH/FSH) which can reduce seminal fluid production from accessory glands. Volume may decrease on cycle but is typically the least affected semen parameter. HCG use on cycle helps maintain testicular contribution to volume. Recovery is usually relatively quick post-PCT compared to concentration and motility.

Number of spermatozoa per milliliter of ejaculate. WHO 6th edition lower reference limit is 16,000,000/mL (16 million/mL).

PED: CRITICAL: AAS cause profound suppression of spermatogenesis via HPT axis shutdown. FSH suppression removes the primary signal for Sertoli cells to support sperm development. Most AAS users become severely oligospermic (<5 million/mL) or azoospermic (zero sperm) within 2-3 months of cycle start. HCG maintains intratesticular testosterone but does not fully preserve spermatogenesis without FSH. Recovery post-PCT is highly variable: 6-12 months typical, but some users experience prolonged or incomplete recovery. Values near zero on cycle are expected and not alarming if temporary.

Percentage of sperm showing any movement (progressive + non-progressive). WHO 6th edition lower reference limit is 42%.

PED: Motility is severely impaired by AAS-induced hormonal disruption. Even residual sperm during AAS use often show poor motility due to disrupted epididymal maturation from low intratesticular testosterone. During recovery post-PCT, motility typically lags behind concentration recovery — sperm may return before quality does. HCG on cycle provides some protection. Values near zero on cycle are expected.

Percentage of sperm moving actively forward. WHO 6th edition lower reference limit is 30%. Most clinically relevant motility parameter for natural conception.

PED: Progressive motility is the most functionally important parameter for fertility — sperm must swim forward to reach the egg. AAS suppress this severely. During recovery, progressive motility is often the slowest parameter to normalise. A semen analysis showing adequate concentration but poor progressive motility still indicates impaired fertility. Monitor this marker closely during PCT and recovery if fertility is a goal.

Acidity of the ejaculate. Reflects the balance between the alkaline seminal vesicle fluid and the acidic prostatic secretion.

PED: Rarely abnormal and rarely acted on in isolation, but it becomes genuinely useful in one specific situation: a low volume, acidic, sperm-free sample points toward obstruction or absence of the vas deferens or seminal vesicles rather than a production problem. That distinction matters because it separates a plumbing issue from a spermatogenesis issue, and the two have completely different management. Alkaline pH above about 8 is more often infection or inflammation. On its own an odd pH means little; read it with volume and count.

Motile sperm sticking to each other, head to head or tail to tail. Distinct from aggregation, where sperm clump to debris or immotile cells.

PED: The reason this is on the report is that agglutination is the classic screening clue for anti-sperm antibodies, an immune cause of infertility that a count and motility check will not reveal. Antibodies can follow testicular trauma, infection, torsion, biopsy or vasectomy including reversal, all of which are more common in this population than average. It is graded rather than measured, so a result of 0 is what you want and anything persistent warrants an anti-sperm antibody test rather than a supplement.

Sperm clumping to mucus, debris or non-motile cells, rather than to each other. Less specific than agglutination.

PED: Usually non-specific and much less concerning than agglutination, but persistent aggregation alongside raised white cells can point to genital tract inflammation or infection, which is itself a driver of DNA fragmentation. Read it with the rest of the sample rather than on its own.

The percentage of sperm showing no movement at all. Grade d in the WHO a/b/c/d motility classification, and the arithmetic complement of total motility.

PED: Carries no information beyond total motility when everything is working, since the grades sum to 100%. It becomes interesting when it is very high, because a near-total absence of movement raises questions a motility percentage alone does not: are the sperm dead, or alive but unable to move? That distinction matters. Alive-but-immotile points toward structural problems such as primary ciliary dyskinesia, whereas dead sperm point toward toxic, thermal or oxidative insult. Labs typically run a vitality test when total motility falls below about 20% for exactly this reason.

How fast sperm actually travel, measured by computer-assisted semen analysis. Reported by labs running CASA systems such as the Hamilton-Thorne IVOS.

PED: Only appears on reports from labs using computer-assisted analysis, so it is absent from most manual semen analyses. It adds a little to progressive motility by describing speed rather than just direction: sperm can be graded progressive while moving too slowly to be useful. Interpret it against the reference the analysing lab printed, because CASA parameters are not standardised across machines and a number from one system does not transfer to another.

The share of sperm with head defects. Reported as a breakdown of the abnormal forms, not as a share of all sperm.

PED: Deliberately carries no reference range, because it is descriptive rather than pass or fail. Under strict Kruger criteria only about 4% of sperm are normal even in fertile men, so a figure like 96% here is arithmetic, not alarm: almost every abnormal sperm has some head irregularity. Judge morphology from [Sperm Morphology](/markers/fertility/sperm-morphology) and the [Teratozoospermia Index](/markers/fertility/teratozoospermia-index) instead. Head defects are the sub-type most linked to fertilisation failure, since the head carries the DNA and the acrosome, so a high head-defect share alongside high DNA fragmentation is a more meaningful pairing than either alone.

The share of abnormal sperm with mid-piece defects. The mid-piece houses the mitochondria that power movement.

PED: No reference range, for the same reason as the other morphology sub-types: it is a breakdown of the abnormal forms, not a pass or fail. Its interest is mechanistic. The mid-piece contains the mitochondria, so mid-piece defects tend to travel with poor motility and poor velocity, and both respond to the same mitochondrial support. Excess residual cytoplasm is usually reported nearby and is the more informative of the two.

The share of abnormal sperm with tail defects: coiled, bent, short or doubled flagella.

PED: No reference range, as with the other morphology sub-types. Generally the least clinically weighty of the three, though coiled tails specifically are worth noting because they are associated with osmotic stress and with prolonged abstinence, both of which are easy to change. A high coiled-tail share is one of the few morphology findings with a straightforward practical fix.

Sperm retaining surplus cytoplasm around the mid-piece, a sign they were released before finishing maturation.

PED: The most informative of the morphology sub-types and the one most worth understanding. Retained cytoplasm is not merely cosmetic: it is loaded with enzymes that generate reactive oxygen species, so these sperm actively produce oxidative stress inside the sample rather than just tolerating it. That makes excess residual cytoplasm a mechanistic link to DNA fragmentation, and a plausible explanation when fragmentation is high while count and motility look acceptable. It reflects spermatogenesis being rushed or disrupted, which is exactly what suppression, heat and varicocele do.

The percentage of sperm carrying fragmented DNA. A standard semen analysis counts sperm and looks at how they swim and how they are shaped; this looks at whether the genetic payload is intact, which those measures cannot detect.

PED: This is the parameter most often missed in enhanced athletes, because a semen analysis can come back entirely normal while fragmentation is high. Count, motility and morphology describe the delivery; fragmentation describes the cargo. The main driver is oxidative stress in the epididymis, which is why it responds to things a normal semen analysis does not: heat, smoking, varicocele, infection, obesity, age, and long abstinence. AAS use matters indirectly. Suppressed intratesticular testosterone impairs spermatogenesis, and a stressed spermatogenic environment produces more fragmentation, but the bigger practical issue is that men often check a semen analysis post-cycle, see acceptable numbers, and assume fertility has recovered. Elevated fragmentation is associated with lower natural conception rates, lower IVF fertilisation and higher miscarriage risk even when conventional parameters look fine. Because the spermatogenic cycle is roughly 74 days, nothing you change today shows up for about three months, so retest at 3 months rather than 3 weeks. Methods differ (Halosperm, SCSA, TUNEL, comet) and their thresholds are not interchangeable, so compare against the range your own lab printed rather than a number from a forum.

Sperm concentration multiplied by semen volume, giving the total number of sperm in the whole ejaculate. WHO lower reference limit is 39 million.

PED: Often a better measure than concentration alone, because concentration is diluted or concentrated by whatever volume the accessory glands happened to produce that day. A man with a low concentration but a large volume can have a perfectly normal total count. On suppressive compounds this falls along with concentration and is one of the clearest numbers to track through recovery, since it captures both the volume and concentration effects in a single figure.

Volume multiplied by concentration multiplied by motility: the number of actually moving sperm in the whole ejaculate. Widely used to decide between natural conception, IUI and IVF.

PED: The single most practically useful number on a semen analysis, because it combines the three parameters that matter into one figure and maps directly onto treatment decisions. Rough clinical bands: above 20 million is generally reassuring for natural conception, 5 to 20 million is where IUI is typically considered, and below about 5 million tends to push toward IVF or ICSI. It falls hard on suppressive compounds and recovers as concentration and motility recover. If you track one fertility number through a recovery protocol, this is the one, since it will not flatter you the way an isolated normal-looking concentration can.

The average number of defects per abnormal sperm. A single sperm can have a head defect, a mid-piece defect and a tail defect at once, and this captures how many faults the abnormal ones carry on average.

PED: Reported alongside morphology by labs using strict WHO criteria, and usually flagged above about 1.80. It adds information morphology alone does not: two men can both have 4% normal forms, but one whose abnormal sperm carry a single minor defect each is in a different position from one whose abnormal sperm are multiply defective. A rising index alongside falling morphology suggests spermatogenesis is under more strain rather than simply producing fewer good cells, which is the pattern seen with suppression, heat and oxidative stress.

Percentage of sperm with normal shape and structure (strict Kruger criteria). WHO lower reference limit is 4%.

PED: Morphology reflects the quality of spermatogenesis. AAS-disrupted hormonal milieu produces abnormal sperm forms (teratozoospermia). Even naturally, only a small percentage of sperm are morphologically normal — the 4% threshold is already low. During AAS use, morphology typically drops below this threshold. Recovery of normal morphology post-PCT can take 3+ months after concentration recovers, as it reflects a full spermatogenic cycle (~74 days). Persistently abnormal morphology after prolonged recovery may warrant fertility specialist referral.

A hormone secreted by the Sertoli cells of the testes that reflects the integrity of the seminiferous tubules and the level of spermatogenesis. It provides negative feedback on pituitary FSH secretion and correlates with sperm production and testicular volume.

PED: One of the most useful markers of testicular reserve in AAS users. Exogenous androgens shut down LH and FSH, which starves the testes of the signals that drive spermatogenesis; inhibin B falls as Sertoli-cell output declines. A low inhibin B in a suppressed athlete signals impaired spermatogenesis and, alongside FSH and sperm analysis, helps predict how readily fertility will recover during a PCT or a restart protocol. A very low or undetectable inhibin B after long or heavy cycles is a warning sign that recovery may be slow or incomplete.

A hormone produced by the granulosa cells of ovarian follicles in women and by the Sertoli cells of the testes in men. In women it is the standard marker of ovarian reserve (the remaining egg supply), and in men it reflects Sertoli-cell mass and testicular function. Levels are relatively stable across the menstrual cycle, which makes AMH a convenient single-draw test.

PED: In men, AMH is a marker of Sertoli-cell function and sits alongside inhibin B and FSH in a fertility workup. Unlike the female picture, adult male AMH is inversely related to intratesticular testosterone: it is high before puberty and is suppressed by the high intratesticular testosterone that normal (or AAS-driven) androgen exposure produces. Because AAS shut down the gonadotropin signals that maintain Sertoli-cell activity and spermatogenesis, a fertility panel in a suppressed athlete is better anchored on inhibin B, FSH, and a semen analysis; AMH is supportive rather than the primary readout in men. For any female users, AMH is the single most useful test of ovarian reserve, important context for those planning fertility while using compounds that disrupt the cycle. Interpret female AMH strictly against age-specific ranges.

Free PSA expressed as a percentage of total PSA. Used to separate benign prostate enlargement from cancer when total PSA sits in the borderline range.

PED: Its whole purpose is to add information when total PSA is equivocal, typically 4 to 10 ug/L, where an elevated result could be benign enlargement or could be cancer. Cancerous tissue produces proportionally more bound PSA, so a LOW ratio is the concerning direction, which is the opposite of how most markers on this site read. Roughly, above 25% is reassuring and below 10% carries substantially higher cancer risk. It matters here because androgens drive prostate growth and both testosterone therapy and long-term AAS use raise total PSA, so enhanced athletes hit that equivocal range more often and more often face an unnecessary biopsy decision. Note this ratio is only interpretable alongside total PSA: it is meaningless when total PSA is normal, and it does not replace urological assessment.

The pressure in your arteries when the heart contracts. The upper number in a blood pressure reading, and the stronger predictor of cardiovascular risk in adults over 50.

PED: Blood pressure is the most commonly neglected marker in enhanced athletes, and one of the few that can cause harm silently for years. Almost every AAS raises it, through some combination of water and sodium retention (oestrogenic and mineralocorticoid activity), raised haematocrit thickening the blood, reduced arterial compliance, and direct effects on the renin-angiotensin system. Trenbolone, oral 17-alpha-alkylated compounds, and anything driving haematocrit hard are the usual offenders. Stimulants (clenbuterol, ephedrine, high-dose caffeine) and GH stack on top of that. The bodybuilder target is NOT more lenient than the general target: hypertension damages kidneys, heart, and eyes at the same rate regardless of how much muscle you carry. Measure seated, after five minutes rest, arm supported at heart level, and take the average of two or three readings rather than reacting to a single spike.

The pressure remaining in your arteries between heartbeats, while the heart refills. The lower number in a blood pressure reading, and the more informative of the two in adults under 50.

PED: Diastolic pressure reflects baseline arterial resistance, so a raised diastolic in a younger lifter often shows up before systolic drifts and is an early sign of reduced arterial compliance. AAS use is associated with increased aortic stiffness independent of the absolute pressure reading. Rising diastolic alongside a normal systolic still deserves attention. As with systolic, the target for enhanced athletes is the standard target: carrying more muscle does not protect the kidneys or the retina.

How many times your heart beats per minute at rest. Reported by most home blood pressure monitors as the third number alongside systolic and diastolic.

PED: Resting heart rate is the cheapest early warning system an enhanced athlete has. It rises before most lab markers move, and a jump of 10-15 bpm above your own baseline is meaningful even when the absolute number still reads normal, which is why tracking your own trend beats comparing against a population range. Trenbolone is the compound most associated with a raised resting pulse, often alongside night sweats and poor sleep. Clenbuterol and other beta-2 agonists raise it directly, as do T3 and T4, ephedrine, yohimbine and high-dose caffeine. Non-drug causes matter just as much: rising resting heart rate is a classic sign of accumulated fatigue and inadequate recovery, and it also rises with dehydration, a heavy cut, illness, and anaemia (where the heart compensates for reduced oxygen-carrying capacity). Note that a well-trained athlete legitimately sits in the 40s and 50s, so the enhanced-athlete range here is wider at the bottom than the standard clinical range. Measure it the same way each time, seated after five minutes rest, ideally first thing in the morning.

Total body mass. Recorded to give context to other markers rather than judged on its own, since there is no clinically meaningful reference range for what a person should weigh.

PED: Weight is deliberately left without a reference range here. What a person should weigh depends entirely on height, frame, training age and what phase they are in, so flagging a bodyweight as high or low would be meaningless. It is tracked because it changes how other numbers are read. Creatinine scales with muscle mass, which is exactly why a lean 110kg lifter can show a creatinine that looks alarming on a standard range and why Cystatin C is the better kidney marker in this population. Several compounds are dosed per kilogram, so a weight recorded alongside your bloods makes those doses reconstructable later. On GLP-1 medications weight is the outcome measure, and pairing it with HbA1c and lipids shows whether the metabolic improvement tracked the weight loss. Blood pressure falls by roughly 1 mmHg per kilogram lost in people carrying excess weight. Read the trend rather than any single reading: day-to-day swings of 1-3kg are water, glycogen and gut content, not tissue. Weigh yourself the same way each time, ideally first thing in the morning after the toilet and before eating or drinking.

Essential vitamin for bone health, immune function, and hormone production.

PED: Many athletes are deficient despite supplement use. Important for testosterone production, immune function, bone health, and mood. Aim for 75-150 nmol/L for optimal performance and hormonal health.

Essential vitamin for nerve function and red blood cell production.

PED: Important for energy, recovery, nerve function, and red blood cell production. Deficiency causes fatigue, neurological symptoms, and elevated homocysteine (cardiovascular risk). Critical for homocysteine metabolism alongside Folate and B6.

B vitamin essential for DNA synthesis and red blood cell production.

PED: Important for red blood cell production, DNA synthesis, and homocysteine metabolism. Adequate levels support recovery. Critical alongside B12 and B6 for keeping homocysteine levels in check (elevated homocysteine is an independent cardiovascular risk factor).

Folate concentration inside red blood cells. Reflects tissue folate status over the previous 3-4 months (the RBC lifespan), making it a more stable marker of long-term folate stores than serum folate, which mirrors recent dietary intake.

PED: Most athletes do not need this test if serum folate is adequate. It becomes useful when serum folate is borderline, when macrocytic anaemia is present, or when long-term folate status needs confirmation independent of recent supplementation. Heavy training and AAS-driven erythropoiesis increase folate demand for DNA synthesis in new red cells. Methylfolate and folic acid both raise this marker, although MTHFR polymorphisms affect how efficiently folic acid is converted. Pair with B12 (cobalamin) and homocysteine for a full one-carbon metabolism picture, since isolated folate repletion can mask B12 deficiency and worsen neurological symptoms.

Enzyme found predominantly in skeletal muscle, cardiac muscle, and brain. The most sensitive marker of skeletal muscle damage, used to diagnose rhabdomyolysis and myopathies.

PED: Heavy resistance training routinely elevates CK to 500-2000 U/L within 24-72 hours. This is physiological, not pathological. AAS can potentiate exertional rhabdomyolysis — case reports document AAS-induced myopathy with extreme CK (>10,000 U/L). Trenbolone is particularly associated with higher muscle damage. Athletes on statins (prescribed for AAS-worsened lipids) face compounded CK elevation risk. Always draw CK after 48-72 hours of rest for a meaningful baseline.

Cardiac biomarker released from cardiomyocytes in response to myocardial wall stress. Highly sensitive for detecting heart failure, left ventricular hypertrophy, and cardiac dysfunction.

PED: Critical marker for AAS users. AAS cause concentric left ventricular hypertrophy — thickening of the heart wall from chronic hypertension and direct androgen receptor stimulation in cardiac tissue. The HAARLEM study showed 4.9% decline in LV ejection fraction after a 16-week cycle. 58% of AAS users show cardiac remodelling on echo. Trenbolone (BP elevation, severe lipid disruption), boldenone (erythrocytosis increasing cardiac workload), and GH+insulin (cardiomegaly) are the most concerning compounds. Always draw after 48+ hours of rest — intense training transiently elevates NT-proBNP.

Digestive enzyme produced exclusively by pancreatic acinar cells. More specific for pancreatic pathology than total amylase. Elevation suggests pancreatic injury or pancreatitis.

PED: 17-alpha-alkylated oral AAS can cause both hepatic and pancreatic injury. Case reports document acute pancreatitis from methandrostenolone (Dianabol) and trenbolone acetate — one case showed recurrence on re-exposure, confirming causation. GH stimulates pancreatic enzyme production; at bodybuilding doses (4-10 IU/day) risk is elevated. Exogenous insulin increases pancreatic amylase by ~61% and lipase by ~47%. The GH + insulin combination is the most concerning protocol for pancreatic health. GLP-1 agonists (semaglutide) have also been investigated for pancreatitis risk.

Pancreatic enzyme that hydrolyses triglycerides. More sensitive and specific for pancreatic pathology than amylase. The preferred diagnostic marker for acute pancreatitis.

PED: GLP-1 receptor agonists (semaglutide, tirzepatide, retatrutide) cause pharmacological lipase elevations of 28-31% without clinical pancreatitis in the vast majority of users. Up to 8.3% of GLP-1 users will exceed 3x the upper limit of normal. GH at bodybuilding doses (4-10 IU/day) stimulates pancreatic enzyme production; exogenous insulin increases lipase by approximately 47%. Oral 17-alpha-alkylated AAS can cause pancreatitis through cholestatic and direct toxic mechanisms. Hypertriglyceridemia above 11.3 mmol/L is an independent pancreatitis risk factor, relevant for athletes on lipid-worsening compounds.

A protein normally produced by the fetal liver and yolk sac that falls to low levels after birth. In adults it is used as a tumour marker, principally for hepatocellular carcinoma (primary liver cancer) and for certain testicular germ-cell tumours, and it can also rise with benign liver injury.

PED: Relevant to long-term AAS users because of liver risk. Oral 17-alpha-alkylated steroids are associated with cholestasis, hepatic adenomas, peliosis hepatis, and, rarely, hepatocellular carcinoma; AFP is one screening tool for liver tumours alongside imaging. Note that AFP also rises modestly with ordinary hepatocyte regeneration, so a mild elevation during a period of raised liver enzymes may reflect benign liver stress rather than cancer. In men it is also part of the germ-cell tumour panel alongside beta-hCG and LDH.

A glycoprotein produced in fetal gut tissue and present at low levels in healthy adults. It is used mainly as a tumour marker for colorectal cancer, where it helps monitor treatment response and detect recurrence, and can also rise with several other cancers and with benign conditions.

PED: Not a PED-specific marker, but it appears on broad screening panels that athletes sometimes order. The single most important interpretive point for this group is smoking: cigarette smokers have higher baseline CEA, so the non-smoker cutoff (about 3 ng/mL) should be relaxed to roughly 5 ng/mL in smokers. CEA is a monitoring tool, not a screening test for healthy people, and mild elevations are far more often benign (smoking, inflammation, liver or lung disease) than malignant.

A carbohydrate tumour-associated antigen used chiefly as a marker for pancreatic and biliary tract cancers, and sometimes to monitor other gastrointestinal malignancies. It is most useful for monitoring a known cancer rather than screening healthy people.

PED: Appears on comprehensive panels but has little PED-specific relevance. The key interpretive caveats: individuals who are Lewis-antigen negative (roughly 5-10% of people) cannot produce CA 19-9 at all, so a normal value never excludes disease in them, and benign obstructive or inflammatory conditions of the bile ducts, pancreas, or liver can raise it substantially. Treat a mild isolated elevation in a healthy athlete as far more likely benign than sinister.

A tumour-associated glycoprotein antigen used mainly as a marker for gastric (stomach) cancer, and sometimes ovarian and other gastrointestinal cancers. It is chiefly used to monitor known disease rather than to screen.

PED: Uncommon on athlete panels and with no PED-specific link. Its practical quirks: CA 72-4 can be transiently raised by benign gastrointestinal conditions and, notably, by some medications and supplements (proton pump inhibitors and colchicine have been reported to affect levels), so a mild isolated elevation is usually not meaningful. It is most often ordered alongside CEA and CA 19-9 for gastric cancer monitoring.

A tumour-associated antigen (a subfraction of TA-4) used as a marker for squamous cell carcinomas, most notably of the uterine cervix, and also of the head and neck, lung, and oesophagus. It is used to monitor known squamous cancers rather than to screen.

PED: Rare on athlete panels and without PED relevance. The main interpretive trap is that benign skin and mucosal conditions raise it: psoriasis, eczema, and other dermatoses, as well as benign lung and liver disease and renal impairment, can all elevate SCC antigen. Given how common skin conditions are in gym-going populations (including acne and steroid-related skin changes), a mild isolated elevation is usually benign.

The biologically active fraction of vitamin B12, bound to transcobalamin and available for uptake by cells. It differs from the standard total Vitamin B12 test, which also measures B12 bound to haptocorrin that cells cannot use. Active B12 is considered a more sensitive early indicator of true B12 status.

PED: Useful when total B12 is borderline or gives a confusing picture. Bodybuilders commonly supplement or inject B12 for energy and recovery, which raises total B12 and can mask an underlying functional deficiency; measuring active B12 (holotranscobalamin) alongside functional markers like homocysteine and methylmalonic acid gives a truer read of whether tissues are actually getting enough. Vegan or plant-heavy athletes, and those on metformin or long-term acid suppression, are at higher risk of true deficiency.

The serum level of retinol, the circulating form of vitamin A. Vitamin A is a fat-soluble vitamin essential for vision, immune function, skin and epithelial health, and cellular differentiation. Both deficiency and excess cause clinical problems.

PED: Two angles matter for this population. First, vitamin A supports skin turnover and immune function, and its derivatives (retinoids like isotretinoin) are widely used for the acne that AAS often worsen; that overlap raises the risk of stacking retinoid exposure. Second, vitamin A is fat-soluble and accumulates: high-dose supplementation or heavy liver/organ-meat intake can cause hepatotoxic vitamin A excess, which is a concern in users who already stress the liver with oral steroids. Do not megadose vitamin A on top of a hepatotoxic cycle.

The serum level of selenium, an essential trace element and cofactor for antioxidant selenoenzymes (glutathione peroxidases) and for the deiodinases that convert thyroid hormone T4 to active T3. This entry tracks the measured blood level, distinct from selenium taken as a supplement.

PED: Selenium is frequently recommended as a supplement on this platform for thyroid support and antioxidant defence, so athletes who follow that advice may want to confirm they are in range rather than over-supplementing. The therapeutic window is narrow: enough selenium supports T4-to-T3 conversion and glutathione peroxidase activity, but chronic excess (selenosis) causes hair and nail loss, garlic breath, and neuropathy. High-dose 'thyroid' or 'antioxidant' stacks can push intake into the toxic range.

The main copper-carrying protein in blood, holding roughly 90% of circulating copper and also acting as a ferroxidase in iron metabolism. It is measured chiefly to help diagnose Wilson's disease (copper overload) and to assess copper status, and it behaves as an acute-phase reactant.

PED: Not a routine PED marker, but it interacts with two things athletes care about. It is an acute-phase reactant, so it rises with inflammation and can also be elevated by high oestrogen states, which matters for AAS users running aromatising compounds or those with elevated oestradiol. It also links copper and iron handling, relevant to enhanced athletes who supplement iron heavily or run copper peptides. A low ceruloplasmin in a young person with liver or neurological symptoms should prompt evaluation for Wilson's disease.

The main antibody class guarding mucosal surfaces (gut, respiratory, and urogenital tracts) and also present in serum. Total serum IgA is measured to assess humoral immune status and, importantly, to check for selective IgA deficiency before interpreting IgA-based coeliac antibody tests.

PED: The most practical reason this shows up alongside athlete panels is coeliac testing. The standard coeliac screen (tissue transglutaminase IgA and endomysial IgA) relies on the person making normal amounts of IgA; selective IgA deficiency, which affects roughly 1 in 500 people, produces falsely negative coeliac antibodies. So a total IgA is often drawn with those tests. IgA can also rise with chronic mucosal inflammation, liver disease, and infections.

An antibody test used in the diagnosis of coeliac disease. It detects IgG antibodies against deamidated gliadin peptides, a component of gluten. It is especially valuable because it works even in people who are IgA-deficient, in whom the standard IgA-based coeliac tests can be falsely negative.

PED: Gut symptoms, bloating, and unexplained fatigue or anaemia are common complaints in dieting athletes, and coeliac disease is an under-recognised cause. This IgG-based test is the go-to when total IgA is low (selective IgA deficiency makes tTG-IgA and endomysial IgA unreliable). For accurate results the person must be eating gluten in the weeks before testing; a self-imposed gluten-free diet, common among physique athletes, can normalise the antibodies and hide the diagnosis.

The first-line blood test for coeliac disease. It measures IgA antibodies against tissue transglutaminase, the enzyme targeted by the autoimmune response to gluten. It has high sensitivity and specificity, but depends on the person producing normal amounts of IgA.

PED: The standard coeliac screen, relevant to athletes with unexplained GI symptoms, iron-deficiency anaemia, or difficulty gaining weight. Two caveats matter for this group. First, the test is only valid if the person is eating gluten: physique athletes who have already cut gluten can test falsely negative. Second, it must be interpreted alongside total IgA, because selective IgA deficiency (about 1 in 500 people) makes tTG-IgA falsely negative, in which case an IgG-based test (deamidated gliadin IgG) is used instead.

A highly specific confirmatory test for coeliac disease, reported qualitatively as positive, negative, or equivocal. It detects IgA antibodies against endomysium (connective tissue around muscle fibres) using an immunofluorescence method, and a positive result is very strongly associated with coeliac disease.

PED: Usually ordered as a confirmatory step after a positive tissue transglutaminase IgA, because its specificity for coeliac disease is very high. Like the other IgA-based coeliac tests, it is only valid while eating gluten and is unreliable in people with selective IgA deficiency (check total IgA). For athletes, the same rule applies: do not go gluten-free before the coeliac workup is complete, or the test can turn falsely negative.

A non-invasive test for active Helicobacter pylori stomach infection. After swallowing urea labelled with carbon-13, the test measures the change in labelled carbon dioxide in the breath (the 'delta' value); H. pylori splits urea and releases the labelled CO2, so a high delta indicates active infection. It is the preferred non-endoscopic test for both diagnosis and confirmation of eradication.

PED: Worth knowing about for athletes with reflux, dyspepsia, or ulcer symptoms, which can be aggravated by heavy NSAID use (common for training aches) and by the gastric stress of very high food volumes. Two practical points: recent proton pump inhibitors, antibiotics, or bismuth can suppress the bacteria and cause a false-negative, so PPIs should be stopped roughly 2 weeks and antibiotics 4 weeks before testing; and the same test is used 4+ weeks after treatment to confirm the infection is cleared.

A protein (MUC16) shed from certain epithelial surfaces, used chiefly as a tumour marker for monitoring epithelial ovarian and peritoneal cancer. It is reported in kIU/L (numerically equivalent to the older U/mL). It is primarily a female-relevant marker.

PED: CA 125 is mainly a female marker: its established role is monitoring known ovarian or peritoneal cancer and following treatment response, not general screening. It has poor specificity, being raised by many benign conditions in women, including menstruation, endometriosis, ovarian cysts, pelvic inflammation, pregnancy, and any cause of peritoneal irritation or ascites. Because of that, it is not a useful screen in people at average risk. In men it has very limited relevance and is only occasionally elevated (for example with peritoneal or pleural inflammation, liver disease with ascites, or heart failure); it appears here because broad wellness panels sometimes include it. For enhanced athletes there is no meaningful PED-specific interpretation. Any genuinely elevated or rising value should be assessed clinically rather than self-interpreted.

A metabolite that accumulates when vitamin B12 is insufficient at the tissue level, because B12 is a required cofactor for the enzyme that converts methylmalonyl-CoA onward. It is a sensitive functional marker of B12 status that can reveal a true deficiency even when serum B12 looks normal.

PED: MMA answers a question serum B12 often cannot: is there enough B12 where the cells actually use it. Serum B12 can sit in the normal range while tissue B12 is inadequate, and in that situation MMA rises early, making it the better test for suspected functional deficiency (fatigue, tingling or numbness, balance or memory changes, unexplained macrocytosis). It complements the Vitamin B12 and Active B12 (holotranscobalamin) markers already in this knowledge base: Active B12 estimates the usable fraction, MMA shows the downstream metabolic consequence of running short. Relevant to bodybuilders because frequent B12 injections are common in the community (which normalise MMA), while strict plant-based diets and metformin use (common with GH/insulin protocols) deplete B12 and can raise MMA. Note MMA also rises with impaired kidney function, so interpret alongside renal markers.

A toxic heavy metal with no safe biological role. Blood lead reflects recent and ongoing exposure, and chronic low-level exposure is linked to hypertension, cardiovascular and kidney harm, and neurological effects. There is no threshold below which lead is known to be completely safe.

PED: For enhanced athletes there is a genuine, often overlooked harm-reduction angle here: underground, gray-market, and unregulated supply chains have no meaningful quality control, and heavy-metal contamination has been documented in some unregulated supplements, imported or counterfeit products, and poorly manufactured underground-lab preparations. Anyone using such products, especially oral compounds or high-volume dosing, carries a real (if variable) contamination risk, and blood lead is a reasonable check. General environmental sources still dominate for most people: old paint and plumbing, contaminated soil and water, some traditional remedies and cosmetics, and occupational exposure (shooting ranges, battery work, renovation). The CDC blood lead reference value is 3.5 mcg/dL, a statistical threshold flagging higher-than-background exposure rather than a safety cut-off. Rising or elevated values should prompt a search for the source.

A toxic heavy metal measured in blood to assess recent exposure, most often to methylmercury from dietary fish and seafood. Chronic elevation is associated with neurological effects and, at higher levels, cardiovascular and renal toxicity.

PED: The dominant source of an elevated blood mercury in a healthy adult is diet, specifically high intake of large predatory fish (tuna, swordfish, king mackerel, shark). That is directly relevant to physique athletes who eat very large amounts of fish for lean protein: someone eating multiple tins of tuna daily can accumulate a genuinely raised mercury over time. Some contaminated or unregulated supplements can also contribute. The fish angle is nuanced, because oily fish also supply the EPA/DHA that benefit cardiovascular and metabolic health, so the goal is smarter species selection rather than cutting fish out. Practical mitigation is to favour low-mercury sources (salmon, sardines, mackerel, shrimp) and rotate protein sources. Reference ranges are lab dependent; toxicity concern rises well above the general-population reference.

Measures arsenic exposure in whole blood. Blood arsenic reflects recent exposure (it clears within a couple of days as arsenic redistributes to tissues), so urine is usually preferred for confirming exposure. Arsenic is a toxic metalloid linked to skin, neurological, and cardiovascular effects and to cancer at chronic exposure.

PED: Arsenic is a genuine contamination concern for enhanced athletes. Underground-lab (UGL) gear, some imported peptides, and low-quality supplements are not always tested for heavy metals, and contaminated products have been documented. Certain protein powders, greens powders, and seafood-derived supplements can also carry arsenic (though dietary organic arsenic from seafood is far less toxic than inorganic arsenic and transiently raises blood levels). A low or undetectable level is normal and healthy, so only high values are meaningful. The bodybuilder range equals the standard range; the difference for PED users is a higher likelihood of exposure through contaminated products, not a different healthy target.

Measures cadmium exposure in whole blood, reflecting relatively recent and ongoing exposure. Cadmium is a toxic heavy metal that accumulates in the kidneys and bones over decades and is strongly associated with cigarette smoke and some contaminated foods and supplements.

PED: Cadmium is not produced by AAS, GH, or peptides, but it is a contamination and lifestyle concern for enhanced athletes. Smoking is by far the biggest driver: smokers typically run several times higher than non-smokers. Some untested supplements (certain plant-based proteins, greens powders, cocoa and shellfish-derived products) and low-quality UGL products can also contribute. Because cadmium concentrates in and damages the kidneys over time, and PED users already stress the kidneys (high protein, high blood pressure, high muscle mass affecting creatinine), keeping cadmium exposure low is sensible harm reduction. A low value is normal; only high values are meaningful. The bodybuilder range equals the standard range.

Plasma ascorbate (vitamin C), a water-soluble antioxidant essential for collagen synthesis, immune function, and iron absorption. Deficiency causes scurvy; it is not stored in large amounts, so status depends on regular intake.

PED: Vitamin C is not directly altered by AAS, GH, or peptides, but low status is common and relevant to lifters. Vitamin C is required for collagen synthesis, so adequacy supports tendon, ligament, and connective-tissue integrity, which matters for athletes under heavy mechanical load and for recovery from injury. Restrictive contest-prep diets low in fruit and vegetables can drive intake down, and smoking and high oxidative stress increase requirements. Vitamin C also enhances non-haem iron absorption, useful for those managing iron status around blood donation. Both low and high results are worth understanding, though high values are usually benign. The bodybuilder range equals the standard range.

Highly specific marker of cardiac muscle injury. Modern high-sensitivity assays detect very small amounts of myocardial damage that older troponin tests missed.

PED: Directly relevant to long-term AAS users. Cardiac troponin I is specific to heart muscle and is not released by skeletal muscle damage from training, so unlike CK and AST it is not confounded by heavy lifting. Long-term AAS use is associated with reduced left ventricular ejection fraction, impaired diastolic function, and accelerated coronary atherosclerosis, and a registry cohort found substantially increased cardiovascular disease risk in steroid users. A persistently detectable hs-troponin in an asymptomatic user is a signal of ongoing subclinical myocardial injury and warrants cardiology input, not reassurance. Note that endurance events can transiently raise troponin for 24-72 hours, so time the draw away from marathon-type efforts.

The most abundant circulating antibody class, making up roughly 75% of serum immunoglobulin. Reflects long-term humoral immunity and is the main marker of antibody deficiency or chronic immune stimulation.

PED: Supraphysiological AAS doses are broadly immunosuppressive, reducing lymphocyte proliferation, antibody production, and natural killer cell activity, with the degree of suppression varying by compound structure. Low IgG in a heavy user with recurrent infections is worth taking seriously rather than attributing to overtraining. Conversely, chronically raised IgG suggests persistent antigenic stimulation: chronic infection, liver disease, or an autoimmune process. Alcohol intake and metabolic abnormalities independently shift immunoglobulin levels, which matters when interpreting a single result.

The first antibody class produced in response to a new infection. A raised IgM points to recent or acute exposure, while a low IgM suggests impaired antibody production.

PED: Measured alongside IgG and IgA as part of an immunoglobulin panel. AAS-driven immunosuppression can lower IgM along with the other classes, and the pattern across all three is more informative than any single value. A raised IgM most often reflects a recent infection rather than anything related to compound use. Persistently elevated IgM with a normal IgG deserves specialist assessment because it can indicate a specific antibody disorder.

The plant and fungal form of vitamin D, measured as its 25-hydroxy metabolite. Reported separately from D3 when a laboratory uses mass spectrometry, and summed with D3 to give total vitamin D.

PED: Essentially undetectable unless you are supplementing with ergocalciferol or taking a prescription high-dose D2 preparation. Most over-the-counter vitamin D in Australia is D3, so a measurable D2 usually means a specific prescription product. D3 raises total 25(OH)D more effectively than D2, particularly when given as a bolus, so anyone relying on D2 to correct a deficiency is likely under-dosing themselves. Interpret this value only as a component of total vitamin D, never on its own.

The form of vitamin D produced in skin from sunlight and found in most supplements, measured as its 25-hydroxy metabolite. In practice it makes up almost all of total vitamin D in people not taking ergocalciferol.

PED: Relevant to athletes beyond bone health: vitamin D status is associated with muscle function, testosterone production, and immune competence, and deficiency is common in anyone training indoors or covering up outdoors. Vitamin D is fat-soluble, so lean, low-body-fat competitors can show different kinetics from the general population, and heavy users of AAS often have suppressed immune function that low vitamin D compounds. If a laboratory reports D2 and D3 separately, add them for the total before judging sufficiency.

A MUC1-derived tumour marker used mainly to monitor treatment response in metastatic breast cancer. Not a screening or diagnostic test.

PED: No established relationship with anabolic steroid, peptide, or growth hormone use. It appears on some comprehensive panels and occasionally in male results, where a mildly raised value is far more likely to reflect a benign cause than cancer. The important point for anyone reading their own panel is that CA 15-3 is not a cancer screening test: levels are rarely raised in early or localised disease, so a normal value excludes nothing, and a mildly raised value in an asymptomatic person usually reflects benign liver or breast conditions rather than malignancy.