The ads do describe the risks. But they are spoken as you watch a vibrant middle-aged man cruising in a convertible with his lady friend, or a peppy guy canoodling with his wife in the kitchen. So it’s easy to focus instead on the prospect of feeling like a teenager again.
That’s a mistake, says John Santa, M.D., director of the Consumer Reports Health Ratings Center. “The risks are substantial,” he says. In a 2010 New England Journal of Medicine study, for example, men 65 and older with low testosterone and obesity or other conditions were treated with Testim 1%. After six months, they had increased physical strength compared with men not on the drug—but they also had more heart attacks and other cardiovascular events.
Other research suggests that the hormone might fuel the growth of prostate cancers. Established risks include blood clots in the legs, sleep apnea, an enlarged prostate, enlarged or painful breasts, and swollen feet or ankles.
Children exposed to testosterone can experience growth of pubic hair, increased libido, and aggressive behavior.
Another concern is reduced sperm counts. “I see men every week who are infertile thanks to testosterone therapy,” says Craig Niederberger, M.D., head of the department of urology at the University of Illinois at Chicago.
The gel forms of testosterone, applied under your arm or on your upper arm and shoulder, can be transferred to others if you don’t wash the area after applying it. Children exposed to the hormone have experienced enlargement of the penis or clitoris, growth of pubic hair, increased libido, and aggressive behavior. Women can experience acne and the growth of body hair and, if they are pregnant or breast-feeding, can transfer the hormone to their babies.