Dehydroepiandrosterone, or DHEA, is an endogenous hormone, meaning it is produced in the body, but production levels vary with age. Children produce very little DHEA. Its production peaks in the 20s, then steadily declines from age 30 or so onward. It is a steroid hormone synthesized from cholesterol in the adrenal glands, and it is responsible for the production of testosterone and estrogen. Supplement makers claim benefits ranging from enhanced sex drive to improved muscle function, though as of 2010, long-term, double blind studies have failed to sufficiently substantiate the claims.
Study results are mixed on the negative effects of a DHEA regimen, but in low doses of 5 mg per day, there is general agreement that DHEA is well tolerated, according to a study by F.A. Huppert and J.K. Van Neikerk published in "The Cochrane Database of Systematic Reviews," in 2006, Issue 1. While the Huppert and Neikerk study sought to link DHEA to increased cognitive function, they found no significant improvement in the test group, but they did determine that no significant side effects presented themselves in the study.
Women taking DHEA, however, have reported unwanted facial hair growth, and some women under age 50 have stopped menstruating, according to John Nestle, M.D., professor of endocrinology and metabolism at Virginia Commonwealth University. Other side effects include acne, irritability and hair loss, but these symptoms were not present in doses as low as 5 mg per day.
Increased Muscle Mass
A study conducted by Samuel Yen, M.D., professor of reproductive medicine at the University of California, San Diego and published in the "Annals of the New York Academy of Sciences," noted improvements in muscle mass and muscle function. Body fat decreased in the men in the study, while it increased slightly in the women. Some control group members taking a placebo also logged an increase in muscle mass, casting some doubt on the results. There was also an increase in markers indicating improved immune system function in both men and women. The study, however, dosed participants at 100 mg per day for a short period, so it is still unclear if a low dose of 5 mg per day taken for a longer period has the same effect. Many supplement makers claim anecdotal evidence affirming those results, even at low doses of 5 mg per day.
Increased Sex Drive
Since DHEA is a precursor to both estrogen and testosterone, it is often suggested as a libido enhancer. In men, decreased levels of testosterone are linked with a low sex drive. Taking 5 mg of DHEA regularly can help boost the testosterone levels by replacing the natural DHEA production, which diminishes with age. Studies on DHEA's efficacy in this area are mixed, however, and no long-term studies of the effects are available.