TRT Side Effects: The Complete, Honest Guide for Australian Men
Key Takeaways
What are the real side effects of TRT? This evidence-based guide covers every documented testosterone replacement therapy side effect — haematocrit, acne, sleep apnoea, fertility — with Australian clinical context.
The Critical Distinction: TRT vs Steroid Misuse
Therapeutic TRT aims to restore testosterone to the normal physiological range. Anabolic steroid misuse involves supraphysiological doses — often 5–20 times higher — for performance enhancement. The extreme side effects associated with "steroids" occur primarily at supraphysiological doses.
The Endocrine Society's 2018 Clinical Practice Guidelines distinguish clearly between the two. For men who genuinely have low testosterone, TRT is a game-changer. For those who don't, the risk-benefit equation changes.
Polycythaemia (Elevated Haematocrit)
Frequency: The most clinically significant TRT-related side effect, occurring in 5–10% of men on injectable testosterone.
Testosterone stimulates red blood cell production via erythropoietin. When haematocrit exceeds 52–54%, blood viscosity increases and thrombotic risk rises theoretically. Healthdirect Australia lists haematocrit elevation as a standard monitoring requirement during TRT.
Management: Monitored at every follow-up. If elevated: dose reduction, switch to gel (lower erythropoietic effect), or therapeutic venesection (blood donation).
The TRAVERSE trial (NEJM, 2023) found no association between haematocrit changes and increased MACE risk, providing important reassurance about real-world outcomes.
Acne and Oily Skin
Frequency: Mild-moderate; common in early treatment particularly in younger men.
Testosterone stimulates sebaceous gland activity. Standard topical acne treatments are effective. Switching from injections (higher testosterone peaks) to daily gels can help in persistent cases.
Testicular Atrophy and Sperm Suppression
Frequency: Near-universal with standard TRT.
Exogenous testosterone suppresses LH and FSH via HPG axis feedback, reducing intratesticular testosterone production and spermatogenesis. For men who want children, HCG co-therapy or sperm banking should be discussed before commencing TRT.
Sleep Apnoea Worsening
Frequency: Rare at therapeutic doses.
Testosterone can worsen or unmask obstructive sleep apnoea. Men with confirmed, treated OSA (CPAP) can generally commence TRT safely.
Mood Changes
Frequency: Uncommon at stable therapeutic levels; more likely with significant hormonal fluctuation.
At stable levels, TRT typically improves mood. The T-Trials (Snyder PJ et al., NEJM 2016) documented significant improvements in depressive symptoms. Irritability is more associated with hormonal peaks from infrequent high-dose injection schedules.
What the Evidence Does NOT Support
Prostate cancer causation: The TRAVERSE trial found no increased prostate cancer incidence in the TRT group.
Heart attack and stroke: As detailed in our cardiovascular safety guide, TRAVERSE demonstrated non-inferiority of TRT to placebo for major adverse cardiovascular events.
References
- Bhasin S, et al. Testosterone Therapy in Men with Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018.
- Snyder PJ, et al. Effects of Testosterone Treatment in Older Men. N Engl J Med. 2016.
- Lincoff AM, et al. Cardiovascular Safety of Testosterone-Replacement Therapy. N Engl J Med. 2023.
- Healthdirect Australia — Testosterone.
- Healthy Male — What is TRT?
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