October 14, 2016 — Testosterone replacement therapy does not provide men with the benefits it is advertised to treat, according to a study published in PLoS One.
Studies do not consistently show that testosterone improves cardiovascular health, sexual function, muscle weakness, mood and behavior, or cognition, according to researchers at Georgetown University.
Their conclusions were based on a systematic review of 156 studies from 1950-2016 in which testosterone was compared to a placebo for at least one of these conditions.
The only thing testosterone consistently improved was muscle strength, but this had no overall physical benefit. According to the authors of the study:
“Testosterone is ineffective in treating erectile dysfunction and controlled trials did not show a consistent effect on libido. … Most studies on mood-related endpoints found no beneficial effect.”
Testosterone therapy is marketed as a cure-all for “Low T,” a syndrome invented by pharmaceutical companies that includes common age-related symptoms like fatigue, depression, sagging muscles, flagging libido, and other ailments.
Testosterone levels normally decrease with age, and that may be a good thing. Testosterone is a hormone that boosts production of red blood cells, which can thicken the blood and increase the risk of blood clots.
In studies of older men, testosterone is associated with higher rates of cardiovascular events. In May 2015, the FDA ordered drug-makers to strengthen warnings about the risk of stroke, heart attack, and death. Over 6,000 federal lawsuits have been filed by men who developed these side effects after using testosterone.