New studies have indicated the increased likelihood of developing blood clots, deep vein thrombosis (DVT) and pulmonary embolisms in individuals receiving testosterone therapy. Blood clots and DVT can lead to pulmonary embolisms, clots that travel to the lungs, which can potentially be life-threatening if not treated promptly.

Testosterone is a crucial hormone responsible for the appropriate development of male sexual characteristics. It is functional in maintaining muscle bulk, sufficient red blood cell supply in the body, proper bone density, psychological well-being, and appropriate sexual and reproductive function.

Testosterone therapy is generally administered to individuals with testosterone deficiency, which can occur due to a variety of reasons, including genetic conditions and physical injury to the testicles. Testosterone also gradually declines with age in men, and is the most dominant cause of testosterone deficiency.

Testosterone drugs already contain labels that warn about the risk of developing blood clots in individuals who suffer from polycythemia. Polycythemia is a rare medical condition that is characterized by abnormally high haemoglobin in blood, and can also be a side effect of taking testosterone supplements.

Despite the existing warning label, the U.S. Food and Drug Administration (FDA) is pushing for a more general label. Also under investigation by the FDA, are the risks and association of heart attack and stroke to testosterone treatment in individuals who do not have any other major pre-existing medical concerns.

While the FDA agrees that the studies do not deem testosterone treatments unsafe, a spokesperson cited the importance of discussing the risks and benefits with a physician to devise the safest possible treatment plan.