Is Testosterone Therapy Safe? What the TRAVERSE Trial Changed
· 6 min read
A man in his twenties with a healthy testosterone level is told he's doing very well. Twenty-five years later, the same man has lost his libido, put on weight around his belly, and his testosterone has dropped sharply. He's told: these are age-related changes.
Why do we call that drop fate? For a long time, one reason doctors hesitated to treat it was concern about the heart. That concern has now been tested properly.
The TRAVERSE trial
TRAVERSE, published in The New England Journal of Medicine in 2023, enrolled 5,246 men aged 45 to 80 with low testosterone and existing heart disease or a high risk of it. Half received testosterone gel and half a placebo, and they were followed for an average of almost three years.
Major cardiac events, such as heart attack, stroke and cardiovascular death, occurred in 7.0% of the testosterone group and 7.3% of the placebo group. In other words, testosterone did not increase the risk.
The FDA's 2025 label change
In February 2025 the US Food and Drug Administration announced class-wide labelling changes for testosterone products. It removed the language in the boxed warning about an increased risk of adverse cardiovascular outcomes and added the TRAVERSE results. It also added a warning about increases in blood pressure.
What it doesn't mean
The trial also found slightly higher rates of atrial fibrillation, pulmonary embolism and acute kidney injury in the testosterone group. And it does not mean testosterone is harmless or that everyone should take it.
Testosterone is not a vitamin. It is not something you buy online, or use at the gym by guesswork without a prior assessment, a measured dose and check-ups afterwards. It must be used under medical supervision, with blood tests before and during treatment.
Who benefits
In the right patient, the benefits are significant: better sex drive, improved bone and muscle metabolism, better mood and more energy. Testosterone also makes other sexual health treatments, such as shockwave therapy, work better.
If you want children soon, tell your doctor: testosterone therapy can lower sperm production. Read more on our testosterone replacement therapy page, or contact us to arrange an assessment.
Frequently asked questions
Does testosterone therapy cause heart attacks?
The TRAVERSE trial found no increase in major cardiac events in men with low testosterone treated with testosterone compared with placebo. Monitoring is still needed, including blood pressure and blood count.
Did the FDA remove the testosterone warning?
In 2025 the FDA removed the cardiovascular-risk language from the boxed warning and added a warning about increased blood pressure.
Can I take testosterone without a prescription?
It isn't safe. Testosterone needs testing beforehand, a measured dose and regular follow-up to avoid side effects.
Sources
- Lincoff et al. Cardiovascular Safety of Testosterone-Replacement Therapy (NEJM, 2023)
- FDA: FDA issues class-wide labeling changes for testosterone products (2025)
- NHS: The 'male menopause'
Medically reviewed by Assoc. Prof. Dr. Alper Kafkaslı, Associate Professor of Urology and Andrology. This article is for general information and does not replace a consultation with a doctor.