An Evidence Based Guide for Australian Men
Why Risk Awareness Matters
Testosterone affects multiple body systems including the cardiovascular system, bone marrow, prostate tissue and reproductive axis. When therapy is prescribed appropriately and monitored correctly, it is generally considered safe for suitable candidates. Problems are more likely to occur when testosterone is used without medical supervision or at supraphysiological doses.
Australian clinical guidance from Healthy Male emphasises careful diagnosis, baseline screening and ongoing monitoring to minimise preventable complications.
Erythrocytosis and Increased Haematocrit
The most consistently observed adverse effect in clinical trials is erythrocytosis, which refers to an increase in red blood cell mass. Testosterone stimulates erythropoietin production and bone marrow activity. While this can be beneficial in men with anaemia, it can also raise haematocrit above safe levels.
A large systematic review published in The Journal of Clinical Endocrinology & Metabolism found that men receiving TRT had a significantly higher likelihood of developing elevated haematocrit compared with placebo.
If haematocrit becomes too high, blood viscosity increases, which may raise the risk of clotting events. This is why regular blood testing is mandatory during treatment. When detected early, elevated haematocrit can be managed by adjusting the dose, changing formulation or temporarily pausing therapy.
Fluid Retention and Sleep Apnoea
Testosterone can promote mild fluid retention in some individuals. This may present as ankle swelling or a sense of bloating. Although typically mild, men with pre-existing heart or kidney disease require closer supervision.
There is also evidence that TRT may worsen untreated obstructive sleep apnoea. Testosterone can influence upper airway muscle tone and respiratory drive. Men with symptoms such as loud snoring, witnessed apnoeas or excessive daytime sleepiness should undergo assessment before starting therapy.
Skin and Mood Changes
Acne and oily skin may occur, particularly in younger men or those using injectable formulations. Mood fluctuations are uncommon when testosterone is maintained within physiological limits but may occur with unstable levels or excessive dosing.
It is important to distinguish medically supervised TRT from anabolic steroid misuse. Supraphysiological testosterone levels are far more likely to produce mood instability and behavioural changes.
Prostate Health Considerations
Testosterone does not cause prostate cancer. However, it can stimulate growth in existing hormone-sensitive prostate tissue. For this reason, TRT is contraindicated in men with untreated prostate or male breast cancer.
Clinical screening prior to therapy typically includes prostate-specific antigen testing and digital rectal examination where appropriate. Ongoing monitoring ensures that any concerning changes are detected early.
Long-term observational data have not shown a consistent increase in prostate cancer incidence among appropriately treated men, but vigilance remains standard clinical practice.
Cardiovascular Risk: What the Latest Evidence Shows
Cardiovascular safety has been debated for more than a decade. Earlier observational studies suggested a potential increase in cardiac events among older men using testosterone. However, these studies had significant methodological limitations.
More recently, the TRAVERSE trial, published in The New England Journal of Medicine, examined men with hypogonadism and existing cardiovascular risk factors. The study found that testosterone therapy was not associated with a higher rate of major adverse cardiovascular events compared with placebo over the follow-up period.
Further discussion in Nature Reviews Urology highlights that while current data are reassuring, long-term surveillance is still necessary, particularly in older men with established heart disease.
Interestingly, untreated low testosterone itself has been associated with higher rates of metabolic syndrome, type 2 diabetes and cardiovascular mortality. Some cohort studies suggest that restoring normal levels may reduce overall mortality in appropriately selected men. Australian commentary from Healthy Male notes that maintaining testosterone within normal physiological ranges appears safer than allowing persistent deficiency in symptomatic men.
Fertility Suppression and the Hormonal Axis
One of the most important but often overlooked risks is fertility suppression. Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal axis. When external testosterone is introduced, the brain reduces luteinising hormone signalling to the testes. As a result, natural testosterone production and sperm production decline.
For men planning children in the near future, this is a critical consideration. Sperm counts can fall significantly during therapy, and recovery after cessation may take months. In some cases, alternative treatments that stimulate endogenous testosterone production may be more appropriate.
Balancing Risk with Documented Benefits
While discussing risks is essential, it is equally important to recognise the documented benefits in properly diagnosed men.
Randomised controlled trials published in JAMA demonstrated improvements in sexual desire, erectile function and sexual activity scores. Studies in JAMA Network Open showed correction of anaemia in hypogonadal men. Increases in bone mineral density have also been documented, reducing future fracture risk.
For many men, improvement in libido and sexual confidence represents a significant quality of life gain. Correction of anaemia can improve exercise tolerance and energy. Bone density improvements may provide long-term protection against osteoporosis.
The key is appropriate patient selection, physiological dosing and consistent monitoring.
Practical Takeaway for Australian Men
TRT is not risk free, but neither is untreated testosterone deficiency. The decision to start therapy should involve:
• Confirmation of persistently low morning testosterone
• Clear and clinically relevant symptoms
• Screening for prostate and cardiovascular risk
• A structured monitoring plan
When prescribed appropriately and supervised carefully, testosterone therapy can provide meaningful benefits with manageable risks.
The most dangerous scenario is not medically supervised TRT. It is unsupervised hormone use without testing, dose control or follow-up.
If you are considering TRT, begin with a comprehensive assessment through your GP or specialist. An informed decision, grounded in evidence, is always better than acting on anecdote.
Sources
The Journal of Clinical Endocrinology & Metabolism. Systematic review and meta-analysis of testosterone therapy in hypogonadal men.
JAMA. The Testosterone Trials investigating sexual function outcomes in older men with low testosterone.
JAMA Network Open. Testosterone therapy and correction of anaemia in hypogonadal men.
The New England Journal of Medicine. TRAVERSE trial evaluating cardiovascular safety of testosterone therapy.
Nature Reviews Urology. Review of cardiovascular considerations and evidence gaps in testosterone therapy.
Healthy Male Australia. Clinical guidance and research summaries on testosterone deficiency and management.
