Testosterone: Benefits, Risks Unknown

Nov. 12, 2003 -- Thousands of middle-aged men are getting testosterone creams, gels, and patches for flagging strength and libido. But there's little evidence that testosterone therapy works for the normal aging male -- or that it's even safe, an expert panel says.

Their report calls for a careful study of the risks and benefits of testosterone therapy in normal aging men. The committee also calls for more prudent prescribing by doctors.

To review and assess what is known about the safety and efficacy of testosterone therapy in older men, the National Institute on Aging and the National Cancer Institute assembled an expert committee of the Institute of Medicine. After a year of study, the committee has recommended going forward with future trials.

"We were struck by the paucity of placebo-controlled trials to identify benefits and risks," said researcher Dan G. Blazer, MD, a professor of psychiatry and behavioral sciences at Duke University Medical Center.

Blazer and members of his committee held a news teleconference today.

It's a hot-button issue -- whether sexual virility, osteoporosis, strength, and stamina are related to the aging male's inevitably declining testosterone level.

Testosterone therapy has been FDA approved for male hypogonadism, a condition of low testosterone production. But many doctors prescribe it for age-related problems such as libido, osteoporosis, fatigue, and overall well-being. It's called "off-label use," and it's legal.

There's a growing number of men seeking treatment with testosterone therapy to counter the effects of aging, but there is little evidence to support this use, says the Institute of Medicine in a news release.

However, testosterone therapy has been linked with prostate cancer, so many doctors are wary of prescribing it. Older men are already at high risk for prostate cancer.

"We live in a society where people are looking for an anti-aging drug, and testosterone is a very popular candidate. ... Testosterone levels do go down as men age," Blazer said. "We're saying, let's get the answers rather than prescribing this drug as a panacea for many of the problems of the aging process."

Eli Chester Ridgway, MD, president of The Endocrine Society and chief of endocrinology at the University of Colorado Health Sciences Center, offered his opinion of the report.

"It's time to cut through the feelings and hopes out there that aging symptoms can be cured by testosterone," Ridgway tells WebMD. "Any practicing endocrinologist wants to know if there truly is a benefit to giving testosterone."

Dramatic Surge in Gel, Patch Prescriptions

An estimated 2 million prescriptions for testosterone therapy were written in 2002 for thousands and thousands of men -- a dramatic increase since the patch and gel were developed, Blazer said. Most were prescribed for middle-aged men.

His committee listened to prominent researchers and reviewed the available scientific literature on testosterone therapy. They identified only 31 trials involving older men. Most studies were quite small with fewer than 50 participants, and only one lasted longer than a year.