Cardiovascular Safety of Testosterone-Replacement Therapy.

Researchers followed 5,246 men aged 45 to 80 who had low testosterone and heart disease or a high risk of it. The men used either testosterone gel or an inactive gel, called a placebo, for about two years. Major heart problems, including heart attacks, strokes, or deaths from heart disease, happened at similar rates in both groups: about 7% of each. The testosterone group had more cases of irregular heartbeat, kidney injury, and blood clots in the lungs.

What this means for you: For men with medically confirmed low testosterone, this study is reassuring about major heart problems over roughly two years, but it does not prove testosterone is safe for lifelong use or improves longevity. It is not a reason to buy testosterone supplements or use treatment without medical guidance.