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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.