DHEA Supplements: What Are They and Are They Safe?

Looking to perk up your sex drive, build some muscle, or fight the effects of aging? You may be considering DHEAsupplements. Before you pull out your wallet, check out our guide to learn what DHEA supplements can and can't do, and what you need to know about their safety.

What is DHEA?

DHEA (dehydroepiandrosterone) is a steroid hormone produced by the adrenal glands. Scientists don't yet know everything DHEA does in the body, but what they do know is that it functions as a precursor to testosterone, the male sex hormone, and estrogen, the female sex hormone. DHEA production peaks in the mid-20s, and in most people, gradually declines with age (as do testosterone and estrogen).

DHEA supplements, made from plant chemicals, work by building up the adrenal gland and regulating the immune system, says Eric R. Braverman, MD, director of the Place for Achieving Total Health (PATH) Medical Centers in New York City and Philadelphia, and author of The Edge Effect and Younger You. Do they really work? That depends what you use them for.

The supplements are most effective when administered in high doses to combat autoimmune conditions such as arthritis and multiple sclerosis (MS), Braverman says. As for other symptoms, such as the normal effects of aging, the jury is still out.

Have we found the fountain of youth in DHEA supplements?

Since DHEA levels decline as we age, some scientists theorize that supplementing our bodies' falling levels of the hormone might help turn back the hands of time. Clinical evidence, including a 2004 study published in the Journal of the American Medical Association, shows they might be right. After 6 months of taking the supplement, older adults experienced significant reductions in abdominal fat and a decrease in insulin resistance.

But a much longer, larger, and more recent study appears to refute the claim. Researchers from the Mayo Clinic examined the effect of DHEA supplementation on markers of aging such as muscle strength and physical performance. The scientists' conclusion: men and women age 60 and up who took the hormone for 2 years showed no measurable improvements in the signs of aging, including body fat, physical performance, insulin sensitivity, and quality of life -- despite the fact that their body content of DHEA increased to levels they likely hadn't seen since their 20s.

The one positive effect was a small improvement in bone density, but at levels much less than what is typically seen with other effective bone-building drugs, say researchers, and then only at participants' wrists.

It's still not known what the natural decline in DHEA has to do with the process of aging, says John E. Morley, MBBCh, Dammert professor of gerontology at St. Louis University Medical School, and director of the Geriatric Research Education and Clinical Center at the St. Louis V.A. Medical Center.

Although there are many studies linking conditions such as diabetes, heart disease, obesity, and Alzheimer's disease with aging, and studies linking increased disease with falling DHEA, there is no scientific proof that DHEA plays any specific role in these phenomena, says Joseph S. Dillon, MD, associate professor of medicine at the University of Iowa Carver College of Medicine.