Two years ago drugmakers spent $14 million promoting prescription testosterone. Last year they spent $100 million. And sales are soaring, topping two billion dollars in 2012. But Consumer Reports says most men don’t need testosterone treatments.

Even if you’re worried about erectile dysfunction, treatment with testosterone usually isn’t the answer. Erectile dysfunction almost always stems from other problems: reduced blood flow, emotional problems, or a drug side effect.

And using testosterone treatments, which can cost $400 a month or more, has serious risks. A study in the New England Journal of Medicine showed that men using one testosterone gel, Testim 1%, for six months had more heart attacks and other cardiovascular events.

Testosterone treatments can have serious side effects, including worsening of enlarged prostate, possible increased risk of prostate cancer, enlarged breasts, sleep apnea, blood clots in the legs, and for younger men, lower fertility.

Consumer Reports’ medical experts say starting testosterone is a big deal. It should only be done after a long and careful conversation between doctor and patient. And there’s another caution: family members being accidently exposed to testosterone gels. The hormone can cause women to develop male characteristics and children to enter an early puberty.

Complete Ratings and recommendations on all kinds of products, including appliances, cars & trucks, and electronic gear, are available on Consumer Reports’ website.