Sales of heavily-advertised testosterone treatments topped $2 billion last  year, but most men don't need it, according to Consumer  Reports.

"Even if you're worried about erectile dysfunction, treatment with testosterone usually isn't the answer," said Dr. John Santa, Consumer Reports' medical adviser. "Erectile dysfunction almost always  stems from other problems: reduced blood flow, emotional problems, or a drug side effect."

Using testosterone treatments, which can cost $400 per month or more, can have 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," Santa said.

The commercials do warn of possible serious side effects, including worsening of enlarged prostrate and possible increased risk of prostate cancer.

Others include enlarged breasts, sleep apnea and blood clots in the legs. JFor younger men, lower fertility is a major concern.

"Starting testosterone is a big deal," Santa said. "It should only be done after a long and careful conversation between doctor and patient."

Another concern is family members being accidentally exposed to testosterone gels.  The hormone can cause women to develop male characteristics and children to enter an early puberty.