Is TRT safe long term?

For men with properly diagnosed low testosterone, current evidence suggests TRT is reasonably safe long term, but it is a medical therapy that needs monitoring, not a shortcut for already-normal levels.

The biggest question about testosterone replacement therapy has always been the heart. For years, conflicting studies left men unsure whether TRT raised cardiovascular risk. That changed with TRAVERSE, published in the New England Journal of Medicine in 2023, the largest trial to date, following more than 5,000 men with low testosterone and existing heart risk for around two years. It found testosterone therapy did not increase the rate of major cardiac events compared with placebo, which is why TRT is prescribed with more confidence today.

But reasonably safe is not the same as risk-free. Long-term TRT carries trade-offs that make monitoring essential:

• It can thicken the blood by raising your haematocrit, which is why regular blood tests matter
• It commonly reduces fertility by shutting down your own sperm production (see can TRT make you infertile)
• It requires ongoing prostate monitoring
• Because it suppresses your natural testosterone, it usually becomes a lifelong commitment, and coming off it can leave you worse than before until your own production recovers

There is also a misuse problem worth naming. TRT is a legitimate treatment for diagnosed low testosterone under medical supervision; it is not a performance enhancer or anti-ageing fix for men whose levels are already normal. Used that way, the balance shifts and the side effects of TRT start to outweigh any benefit.

What to do: if you have genuine symptoms and two low morning blood tests, TRT can be life-changing, but do it properly: a proper diagnosis, regular monitoring of blood count, PSA and hormones, and an honest conversation about fertility first. Many men should also try optimising sleep, body fat and training first, since that is free and reversible, as set out in raising testosterone naturally.