Guys: Have you seen ads lately about topical meds to treat low testosterone levels—or “low T”—as you age? Well, the majority of doctors say the hype over roll-on hormone replacement prescription drugs to boost your sex drive, energy and sports play abilities is at best unproven and, at worst, dangerous to your health, The New York Times reports.

According to a new survey by CMI/Compass, a communications media company, 63 percent of doctors said pharmaceutical advertising of topical testosterone gels has misinformed patients about the meds’ ability to treat the sexual and physical side effects of aging.

Last year alone, American drugmakers spent more than $3 billion on direct-to-consumer ads repositioning testosterone gels as lifestyle products for men, despite the fact that no one has proved yet that the gels work for older men. (The only proven use for testosterone replacement meds is to treat serious hormonal deficiencies caused by medical problems such as endocrine tumors or the negative side effects of chemotherapy.)

What’s more, the medical community has never actually defined what “normal” or “physiological” testosterone levels should be. In addition, doctors also said that testosterone levels naturally decline as men age. For this reason, many docs believe low T is an invented condition that doesn’t need treatment unless testosterone levels are severely deficient because of grave medical issues.

“Until there are big long-term studies to address the issues of testosterone replacement, we’re not ready to make recommendations,” said Joel Finkelstein, MD, an endocrinologist and an associate professor at Harvard Medical School.

Finkelstein said the only findings about testosterone gels that have been proved are the health risks associated with their use. The list of side effects includes an increased risk of coronary artery disease, “ridiculously high” testosterone levels in some patients and an enlarged prostate.

Finally, aging men with erectile dysfunction (ED) should beware the “low T” hype. ED isn’t always linked to low levels of testosterone. Click here to read more.