Does testosterone therapy cause prostate cancer?

This is arguably the most persistent myth in men's hormonal health. The fear has kept generations of men from exploring treatment that might have meaningfully improved their lives. It deserves a direct, evidence-based answer.

Testosterone therapy does not cause prostate cancer.

Where the fear came from.

The concern traces back decades to an era when oncologists observed that castration — dramatically lowering testosterone — caused certain prostate tumors to shrink. The logical leap was that testosterone must therefore fuel prostate cancer growth. That assumption shaped clinical practice for a generation.

The problem is that the assumption was wrong.

The Saturation Model.

Research pioneered by Dr. Abraham Morgentaler at Harvard introduced what is now called the Saturation Model. The model explains that prostate tissue has a finite number of androgen receptors. Once those receptors are saturated — which happens at relatively low testosterone levels — additional testosterone has no further stimulating effect on prostate cell growth. The receptors are already full. More hormone has nowhere to bind.

This is why men with higher testosterone levels do not have higher rates of prostate cancer. And it is why large-scale longitudinal studies, including the 2024 analysis of the TRAVERSE trial, confirm no increased risk of prostate cancer development in men on managed TRT compared to men not on therapy.

Some data suggests that men with chronically low testosterone may actually face a higher risk of more aggressive prostate disease — not the reverse.

How we monitor prostate health.

Understanding the science does not mean skipping the monitoring. At Pure Metabolics, PSA screening is required before starting therapy, and we track it every three to six months. We don't just look at a single number — we track PSA velocity, the rate of change over time, which is a more sensitive indicator of meaningful change than any single reading.

• PSA (Total): Required baseline; monitored every 3–6 months.
• PSA Velocity: We track the trend, not just the number.
• Free PSA %: Ordered if Total PSA shows an unexpected rise.
• Referral threshold: A significant PSA rise triggers referral to a local urologist.

The goal is not to avoid the question of prostate health. It is to answer it continuously, with data, for as long as you are in our care.

Disclaimer: Testosterone therapy does not cause prostate cancer, but may stimulate the growth of a pre-existing, undiagnosed cancer. Regular PSA screening is required. Men with a history of prostate cancer must provide clearance from their oncologist or urologist before starting TRT.