Starting TRT in Australia: Levels by Age, Clinics, and What to Expect

Testosterone replacement therapy has gone from a niche treatment to a mainstream conversation. In the United States alone, TRT prescriptions rose from 7.3 million in 2019 to over 11 million in 2024, with the sharpest growth among men aged 35 to 44 (a 58% increase). The global TRT market is projected to exceed USD 2.5 billion by 2031, with the Asia-Pacific region (including Australia) growing fastest at over 5% annually. In Australia, the landscape is shifting too: private telehealth clinics now operate alongside the traditional PBS pathway, giving men more options than ever.

But more options also means more room to get it wrong. Men are starting TRT without baseline bloodwork, without understanding the fertility implications, and without a monitoring plan. Some are prescribed testosterone by clinics that disappear after the first script. Others avoid treatment entirely because they are intimidated by needles or confused by conflicting information online.

This guide covers everything you need to make an informed decision: what normal testosterone levels look like at every age, when TRT is genuinely recommended, what it does to your fertility, how it works in Australia specifically, how to find a clinic that will actually support you, and what the day-to-day reality of injections and blood tests looks like.

Normal Testosterone Levels by Age

Testosterone peaks during late adolescence and early adulthood, then begins a gradual, lifelong decline. The Baltimore Longitudinal Study of Aging, one of the longest-running studies on male hormones, established that total testosterone declines by approximately 1 to 2% per year after age 30 (Harman et al., 2001). Free testosterone, the biologically active fraction not bound to SHBG, declines even faster because SHBG rises with age.

Here is what the research shows for average total testosterone ranges by decade:

Age Range	Average Total Testosterone	Typical Range
18 to 25	600 to 700 ng/dL (20.8 to 24.3 nmol/L)	400 to 900 ng/dL
25 to 35	550 to 650 ng/dL (19.1 to 22.5 nmol/L)	350 to 850 ng/dL
35 to 45	500 to 600 ng/dL (17.3 to 20.8 nmol/L)	300 to 800 ng/dL
45 to 55	430 to 530 ng/dL (14.9 to 18.4 nmol/L)	250 to 750 ng/dL
55 to 65	370 to 470 ng/dL (12.8 to 16.3 nmol/L)	200 to 700 ng/dL
65+	300 to 400 ng/dL (10.4 to 13.9 nmol/L)	150 to 600 ng/dL

These are population averages. Individual variation is enormous. A healthy 50-year-old can have higher testosterone than an unhealthy 25-year-old. Obesity, sleep quality, stress, alcohol use, and chronic illness all suppress testosterone independently of age.

What Is "Normal" vs "Optimal"?

This is where things get contentious. Most Australian pathology labs flag testosterone below 8 nmol/L (approximately 230 ng/dL) as low. The American Urological Association uses 300 ng/dL (10.4 nmol/L) as its threshold for testosterone deficiency (Mulhall et al., 2018). The Endocrine Society uses a similar cutoff (Bhasin et al., 2018).

But a level of 310 ng/dL in a 30-year-old man with fatigue, low libido, brain fog, and poor recovery from training is not "normal" just because it clears an arbitrary threshold. The guidelines themselves acknowledge this: the AUA states that treatment decisions should consider both the lab value and the presence of symptoms.

Free testosterone adds another layer. A man can have a total testosterone of 500 ng/dL but if his SHBG is 70 nmol/L, his free testosterone may be genuinely low. Always request both total and free testosterone (or at minimum total testosterone plus SHBG so free testosterone can be calculated).

When Is TRT Actually Recommended?

TRT is not recommended for age-related decline alone. The clinical indication is hypogonadism: persistently low testosterone levels confirmed on at least two separate morning blood draws, combined with signs and symptoms consistent with testosterone deficiency.

Symptoms That Warrant Investigation

• Reduced or absent libido
• Erectile dysfunction unresponsive to PDE5 inhibitors
• Persistent fatigue and low energy despite adequate sleep
• Loss of muscle mass and strength despite training
• Increased body fat, particularly visceral fat
• Depressed mood, irritability, or cognitive decline ("brain fog")
• Reduced bone mineral density or unexplained fractures
• Loss of body hair or reduced shaving frequency
• Hot flushes (more common in severe deficiency)

The Diagnosis Process

1. Two morning blood tests: Testosterone peaks between 7 and 10 AM and can drop by 25 to 30% by the afternoon. Draw blood fasted, before 10 AM, on two separate occasions at least two weeks apart.
2. Comprehensive panel: Total testosterone alone is insufficient. Request total testosterone, free testosterone (or SHBG for calculation), LH, FSH, oestradiol, prolactin, thyroid function (TSH, free T4), full blood count, and metabolic panel.
3. Rule out secondary causes: High prolactin can suppress testosterone (pituitary adenoma). Obstructive sleep apnoea, obesity, opioid use, and chronic illness are all reversible causes of low testosterone that should be addressed before starting TRT.
4. LH and FSH tell you why: If testosterone is low and LH/FSH are high, the problem is the testes (primary hypogonadism). If testosterone is low and LH/FSH are low or normal, the problem is the pituitary or hypothalamus (secondary hypogonadism). This distinction affects treatment options.

At What Age Should You Consider TRT?

There is no minimum age. Hypogonadism can occur at any age. Congenital conditions (Klinefelter syndrome, undescended testes), pituitary tumours, head injuries, and certain medications can cause low testosterone in men in their 20s and 30s.

That said, the probability increases with age. If you are under 35 and symptomatic, your doctor should be especially thorough in looking for underlying causes before defaulting to TRT. A 28-year-old with low testosterone caused by sleep apnoea and obesity may not need lifelong hormone replacement; he needs a CPAP machine and a caloric deficit.

For men over 40 with confirmed low testosterone and symptoms that impair quality of life, TRT is a well-established treatment with strong evidence of benefit for sexual function, body composition, bone density, and mood (Bhasin et al., 2018).

The Fertility Question

This is the section most clinics gloss over, and it is the one that matters most if you are under 40 or have any interest in future fatherhood.

TRT suppresses sperm production. Exogenous testosterone shuts down the hypothalamic-pituitary-gonadal (HPG) axis. Your brain detects high testosterone from the injection and stops sending LH and FSH to the testes. Without these signals, sperm production slows dramatically or stops entirely. Studies show that up to 90% of men on TRT develop oligospermia (low sperm count) or azoospermia (zero sperm) within 6 to 12 months.

This is not a theoretical risk. It is a near-certainty if you are on testosterone alone without fertility preservation.

Your Options

1. Delay TRT until after family planning is complete. If your symptoms are manageable and you plan to have children in the next 2 to 3 years, this may be the simplest path.

2. Use hCG alongside TRT. Human chorionic gonadotropin (hCG) mimics LH and keeps the testes producing both testosterone and sperm. A dose of 500 to 1,000 IU two to three times per week is the most common protocol. A study by Wenker et al. found that 95.9% of men who had become azoospermic on TRT recovered spermatogenesis using hCG-based combination therapy, with an average recovery time of 4.6 months (Wenker et al., 2015).

3. Consider SERMs as an alternative to TRT. Clomiphene citrate stimulates LH and FSH production, raising endogenous testosterone while preserving fertility. It is sometimes used in younger men with secondary hypogonadism who want to avoid the HPG suppression of exogenous testosterone. The trade-off is that testosterone increases are typically more modest than with TRT.

4. Bank sperm before starting. If you want a guaranteed fallback, sperm cryopreservation before starting TRT provides a safety net. This is straightforward, relatively inexpensive, and removes the uncertainty.

Can You Recover Fertility After Stopping TRT?

Usually, yes, but not always, and not quickly. A review by Patel et al. found that most men recover spermatogenesis within 6 to 12 months of stopping TRT, but some take up to 24 months, and a small percentage may not recover fully, particularly after prolonged use (Patel et al., 2019). hCG and FSH can accelerate recovery, but there are no guarantees.

Consequences and Side Effects of TRT

TRT is generally safe when properly monitored. The 2023 TRAVERSE trial, the largest randomised controlled trial of testosterone therapy ever conducted (5,246 men, mean follow-up 33 months), confirmed that TRT does not increase the risk of major adverse cardiovascular events in men with hypogonadism and pre-existing or high risk of cardiovascular disease (Lincoff et al., 2023). This led to the removal of the FDA's cardiovascular black box warning.

That said, TRT is not without side effects, and you need to know what to watch for.

Polycythaemia (Elevated Red Blood Cells)

This is the most common side effect. Testosterone stimulates erythropoiesis (red blood cell production), which raises haematocrit and haemoglobin. A review by Ohlander et al. found that men on TRT have a 315% greater risk of developing erythrocytosis (haematocrit above 0.52) compared to controls (Ohlander et al., 2016).

Elevated haematocrit increases blood viscosity and raises the risk of thrombotic events (stroke, deep vein thrombosis, pulmonary embolism). This is why regular blood monitoring is non-negotiable. If your haematocrit exceeds 0.54, your doctor will typically reduce your dose, increase injection frequency, or arrange therapeutic phlebotomy (blood donation).

Testicular Atrophy

Without LH stimulation, the testes shrink. This is cosmetic for most men but can be distressing. hCG co-therapy prevents or reverses this.

Acne and Oily Skin

Testosterone increases sebum production. Some men develop acne on the back, shoulders, or face, particularly in the first few months. This usually stabilises as hormone levels reach steady state.

Mood and Psychological Effects

Most men report improved mood, confidence, and motivation on TRT. However, supraphysiological levels or unstable dosing can cause irritability, anxiety, or emotional volatility. Stable blood levels through consistent injection frequency help prevent this.

Oestradiol Elevation

Testosterone aromatises to oestradiol. Some men develop elevated E2 with symptoms like water retention, nipple sensitivity, or mood changes. This is manageable through dose adjustment, increased injection frequency, or (rarely) low-dose anastrozole. Read our full guide on managing estradiol on TRT for details.

The Commitment Factor

TRT is typically a lifelong commitment. Once you start, your endogenous production shuts down. While recovery is possible after stopping (see the fertility section above), it takes months and you will feel significantly worse during the transition. Some men never fully recover their baseline. Go in with eyes open: this is not a short-term experiment.

How TRT Works in Australia

Australia has two main pathways to access testosterone replacement therapy, and they differ significantly in criteria, cost, and process.

The PBS (Pharmaceutical Benefits Scheme) Pathway

Under the PBS, testosterone is subsidised but the eligibility criteria are strict:

• Total testosterone must be below 6 nmol/L (approximately 173 ng/dL) on two separate morning blood tests
• You must have clinical symptoms consistent with hypogonadism
• The prescribing doctor must be an endocrinologist or have specialist authority
• Initial authority is required from Services Australia

At 6 nmol/L, the PBS threshold is well below most international guidelines (the AUA uses 10.4 nmol/L / 300 ng/dL). This means many Australian men with genuine hypogonadism by international standards do not qualify for subsidised treatment.

PBS-approved formulations include:

• Testosterone undecanoate injection (Reandron): 1000 mg intramuscular every 10 to 14 weeks. This is the most commonly prescribed TRT in Australia via PBS. It is a long-acting depot injection administered by a nurse or GP.
• Testosterone cream/gel (Androforte, AndroGel): Applied daily to the skin. Less commonly subsidised.
• Testosterone enanthate and testosterone cypionate: Not PBS-listed in Australia. Available through private prescriptions or compounding pharmacies.

The Private Clinic Pathway

Private TRT clinics have grown rapidly in Australia. They offer:

• Lower diagnostic thresholds: Most private clinics will consider treatment if your testosterone is in the low-normal range (e.g., under 12 to 15 nmol/L) with symptoms, rather than requiring the PBS threshold of 6 nmol/L.
• More formulation options: Private clinics commonly prescribe testosterone enanthate or cypionate for self-injection at home, with weekly or twice-weekly dosing for more stable blood levels.
• Telehealth consultations: Most operate primarily via video call, making them accessible Australia-wide.
• Ongoing monitoring: Good clinics include regular blood work reviews as part of their service.

The trade-off is cost. Expect to pay $1,500 to $2,500 per year for consultations, blood tests, and medication through a private clinic.

Prescription Requirements

Testosterone is a Schedule 4 (prescription-only) and Schedule 8 (controlled drug) substance in Australia. You cannot legally obtain it without a prescription from a registered Australian medical practitioner. Any clinic or source offering testosterone without a prescription is operating outside the law.

Finding the Right Clinic

Not all TRT clinics are equal. Some will prescribe testosterone to anyone who walks through the door without adequate diagnostics. Others will monitor you properly for the first three months and then disappear. Here is what to look for.

Green Flags

• Comprehensive baseline blood work before prescribing (total and free testosterone, LH, FSH, oestradiol, prolactin, full blood count, lipids, liver function, PSA, thyroid function)
• Two separate blood tests before diagnosis, drawn in the morning
• Discussion of fertility and family planning before starting treatment
• A structured monitoring schedule with blood tests at 6 weeks, 3 months, 6 months, and then every 6 to 12 months
• Willingness to adjust the protocol based on your symptoms and blood work, not just a one-size-fits-all approach
• Access to a prescribing doctor (not just a nurse or wellness coach) who you can speak with when issues arise

Red Flags

• Prescribing TRT based on a single blood test or an afternoon draw
• No discussion of fertility or side effects
• Refusing to order or review full blood work
• Pushing additional supplements, peptides, or "hormone optimisation packages" as upsells
• No follow-up monitoring plan after the initial prescription
• Unable to name the prescribing physician

Australian Clinic Options

Several clinics operate nationally via telehealth:

• Enhanced Men's Clinic (enhancedmensclinic.com.au): Over 2,500 patients, telehealth-based, evidence-focused. One of the more established private TRT clinics in Australia.
• TRT Australia (trtaustralia.com): Comprehensive blog content, telehealth consultations, prescribes enanthate and cypionate.
• TRT Doctors Australia (trtdoctors.com.au): Budget-friendly option at approximately $300 per quarterly consultation plus pharmacy costs. Offers a $49 initial blood test.
• The Testo Clinic (thetestoclinic.com.au): Personalised protocols, telehealth-based.
• Low T Clinic (lowtclinic.com.au): Melbourne-based with telehealth services.
• Testosterone Clinic Australia (testosteroneclinic.com.au): Operated by Men's Health Clinic, offers both in-person and telehealth.

The GP Route

You do not need a private clinic. A knowledgeable GP can diagnose hypogonadism, order the necessary blood work, and refer you to an endocrinologist for PBS-subsidised treatment if you qualify. The advantage is lower cost; the disadvantage is that many GPs are unfamiliar with modern TRT protocols and may default to Reandron every 12 weeks without optimising dose or frequency.

If you go the GP route, consider asking for a referral to an endocrinologist with experience in male hypogonadism rather than relying solely on GP-managed care.

Injections: Getting Comfortable and Choosing Your Protocol

For most men on TRT in Australia, the day-to-day reality involves self-administered injections. This is the part that intimidates people the most, and it is also the part that becomes completely routine within a few weeks.

Subcutaneous vs Intramuscular

There are two injection methods:

Intramuscular (IM): The traditional method. A 23 to 25 gauge needle, 1 to 1.5 inches long, injected into the gluteal, deltoid, or vastus lateralis (outer thigh) muscle. This is how testosterone has been administered for decades and is well-studied.

Subcutaneous (SubQ): Increasingly popular. A 27 to 30 gauge needle (insulin syringe), 0.5 inches long, injected into the abdominal or thigh fat. A study published in The Journal of Urology found that SubQ testosterone produces equivalent testosterone levels with lower post-therapy oestradiol and haematocrit compared to IM (Kohn et al., 2022).

SubQ injections are less painful, easier to self-administer, and use smaller needles. Many Australian private clinics now default to SubQ protocols.

Injection Frequency

Frequency matters more than most people realise. The goal is stable blood levels with minimal peaks and troughs.

Protocol	Frequency	Stability	Notes
Reandron (undecanoate)	Every 10 to 14 weeks	Moderate	PBS standard. Long-acting depot. Cannot self-inject (must be administered by a healthcare professional).
Enanthate/Cypionate weekly	Once per week	Good	Most common private clinic protocol.
Enanthate/Cypionate twice weekly	Every 3.5 days	Very good	Reduces E2 spikes and haematocrit rises. Better for high aromatisers.
Enanthate/Cypionate daily (micro-dosing)	Daily	Excellent	Mimics natural circadian rhythm. Growing in popularity. Uses insulin syringes SubQ.

More frequent injections produce more stable blood levels, which generally means fewer side effects (less oestradiol fluctuation, lower haematocrit peaks, more stable mood and energy). The trade-off is more injections per week.

Practical Injection Tips

• Rotate injection sites: Do not inject in the same spot repeatedly. Alternate between left and right thigh, abdomen, or deltoids.
• Use the right needle: For SubQ, 27 to 30 gauge insulin syringes work well. For IM, 23 to 25 gauge, 1 to 1.5 inch.
• Warm the oil: Hold the vial in your hands or run it under warm water for a minute. Warm oil flows more easily through the needle.
• Inject slowly: Push the plunger steadily over 10 to 15 seconds. Rushing causes post-injection pain.
• Do not aspirate: Current evidence-based guidelines no longer recommend aspirating before injection. The WHO removed this recommendation years ago.
• Be consistent: Inject on the same day(s) each week. Set a phone reminder if needed.

Blood Test Monitoring on TRT

Starting TRT without a monitoring plan is like driving without a dashboard. You need regular blood work to ensure your levels are therapeutic, your side effects are manageable, and nothing dangerous is developing silently.

What to Test and When

The Endocrine Society and AUA guidelines recommend the following monitoring schedule (Bhasin et al., 2018) (Mulhall et al., 2018):

Baseline (before starting TRT):

• Total and free testosterone (two morning draws)
• LH and FSH
• Oestradiol
• Prolactin
• Full blood count (haematocrit, haemoglobin, RBC)
• PSA (men over 40)
• Lipid panel (HDL, LDL, triglycerides)
• Liver function (ALT, AST)
• Kidney function (creatinine, eGFR)
• Thyroid function (TSH)
• Fasting glucose and HbA1c

6 weeks after starting:

• Total and free testosterone (drawn at trough, i.e., the morning before your next injection)
• Haematocrit and haemoglobin
• Oestradiol
• PSA (if baseline was elevated)

3 months:

• Full panel repeat (all baseline markers)
• Assess symptoms and adjust dose if needed

6 months:

• Full panel repeat
• PSA

Ongoing (every 6 to 12 months):

• Total and free testosterone
• Full blood count (haematocrit is the priority)
• PSA (annually for men over 40)
• Oestradiol
• Lipid panel (annually)
• Metabolic panel (annually)

When to Draw Blood

Timing matters. For testosterone enanthate or cypionate on a weekly protocol, draw blood the morning before your next injection (trough level). This gives your doctor the lowest point of your cycle, which is the most clinically useful number. If your trough is in the mid-normal range, your average level throughout the week is well within the therapeutic range.

For Reandron (undecanoate), draw blood the week before your next injection to assess the trough.

For twice-weekly or daily protocols, timing is less critical since levels are more stable. Draw in the morning, fasted, before any injection that day.

What the Numbers Should Look Like on TRT

• Total testosterone: 15 to 30 nmol/L (430 to 865 ng/dL) at trough. The goal is mid-normal, not supraphysiological.
• Free testosterone: Upper half of the reference range
• Oestradiol: 70 to 180 pmol/L (19 to 49 pg/mL). Treat symptoms, not numbers.
• Haematocrit: Below 0.52 (52%). Action required above 0.54.
• PSA: Stable. A rise of more than 1.4 ug/L within 12 months or an absolute value above 4.0 ug/L warrants urological referral.

Key Takeaways

• Testosterone declines by 1 to 2% per year after age 30, but there is no single "normal" level. Symptoms matter as much as numbers.
• TRT is recommended when you have both persistently low testosterone (confirmed on two morning blood draws) and symptoms that impair quality of life.
• TRT suppresses fertility. If future fatherhood is on the table, discuss hCG co-therapy, clomiphene as an alternative, or sperm banking before starting.
• The TRAVERSE trial (2023) confirmed that TRT does not increase cardiovascular risk in appropriately selected men, but polycythaemia, oestradiol elevation, and testicular atrophy still require monitoring.
• In Australia, the PBS pathway requires testosterone below 6 nmol/L. Private clinics offer more flexibility but cost $1,500 to $2,500 per year.
• Choose a clinic that orders comprehensive baseline blood work, discusses fertility, and has a structured monitoring plan. If they skip these steps, find someone else.
• SubQ injections with insulin syringes are painless, effective, and increasingly the standard of care. Twice-weekly or daily dosing produces the most stable blood levels.
• Blood tests every 3 to 6 months in the first year, then every 6 to 12 months ongoing. Haematocrit is the most important safety marker to track.
• TRT is typically a lifelong commitment. Make sure you are informed, supported, and monitored before you start.

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References

1. Harman, S. M., Metter, E. J., Tobin, J. D., Pearson, J., & Blackman, M. R. (2001). Longitudinal effects of aging on serum total and free testosterone levels in healthy men. The Journal of Clinical Endocrinology & Metabolism, 86(2), 724-731. PubMed

2. Travison, T. G., Araujo, A. B., O'Donnell, A. B., Kupelian, V., & McKinlay, J. B. (2007). A population-level decline in serum testosterone levels in American men. The Journal of Clinical Endocrinology & Metabolism, 92(1), 196-202. PubMed

3. Bhasin, S., Brito, J. P., Cunningham, G. R., Hayes, F. J., Hodis, H. N., Matsumoto, A. M., ... & Yialamas, M. A. (2018). Testosterone therapy in men with hypogonadism: An Endocrine Society clinical practice guideline. The Journal of Clinical Endocrinology & Metabolism, 103(5), 1715-1744. PubMed

4. Mulhall, J. P., Trost, L. W., Brannigan, R. E., Kurber, E. G., Redmon, J. B., Chiles, K. A., ... & Jarowenko, M. V. (2018). Evaluation and management of testosterone deficiency: AUA guideline. The Journal of Urology, 200(2), 423-432. PubMed

5. Lincoff, A. M., Bhasin, S., Flevaris, P., Mitchell, L. M., Basaria, S., Boden, W. E., ... & Nissen, S. E. (2023). Cardiovascular safety of testosterone-replacement therapy. The New England Journal of Medicine, 389(2), 107-117. PubMed

6. Wenker, E. P., Dupree, J. M., Langille, G. M., Kovac, J., Ramasamy, R., Lamb, D., ... & Lipshultz, L. I. (2015). The use of HCG-based combination therapy for recovery of spermatogenesis after testosterone use. The Journal of Sexual Medicine, 12(6), 1334-1337. PubMed

7. Patel, A. S., Leong, J. Y., Ramos, L., & Ramasamy, R. (2019). Testosterone is a contraceptive and should not be used in men who desire fertility. The World Journal of Men's Health, 37(1), 45-54. PubMed

8. Ohlander, S. J., Varghese, B., & Ganesan, V. (2016). Erythrocytosis and polycythemia secondary to testosterone replacement therapy in the aging male. Sexual Medicine Reviews, 4(4), 304-312. PubMed

9. Kohn, T. P., Mata, D. A., Ramasamy, R., & Lipshultz, L. I. (2022). Testosterone therapy with subcutaneous injections: A safe, practical, and reasonable option. The Journal of Urology, 207(4), 719-720. PMC

10. Sansone, A., Sansone, M., Vaamonde, D., Sgro, P., Salzano, C., Romanelli, F., ... & Di Luigi, L. (2022). Secondary polycythemia in men receiving testosterone therapy increases risk of major adverse cardiovascular events and venous thromboembolism in the first year of therapy. The Journal of Urology, 207(1), 161-168. PubMed