By age seventy-five, DHEA levels are only 10 to 20 percent of what they were at age twenty.

DHEA is produced by the adrenal glands. Production of DHEA is high even when the fetus is still developing. Our body's DHEA levels continue to rise up to about age twenty-five, when production drops off sharply. As with melatonin and human growth hormone (HGH), falling levels of DHEA are closely associated with a number of age-related diseases and disabilities. Scientists speculate that if aging men and women can restore their DHEA to youthful levels, their youthful health and vigor will also be restored.

According to Dr. Samuel Yen, reproductive endocrinologist and principal investigator of a DHEA study at the University of California at San Diego, DHEA is "a drug that may help people age more gracefully." When taking DHEA, 82 percent of women and 67 percent of men scored higher tests rating their ability to cope with stress, their quality of sleep, and their basic well-being. Only 10 percent of the group not receiving the hormone reported feeling any better.

Small amounts of DHEA were found to lessen amnesia and enhance long-term memory in mice. Even very low levels of DHEA supplementation may increase the number of neurons in the brain as well as prevent neuronal loss and/or damage.
If DHEA decreases with age, increasing our levels later in life may be the answer. Dr. William Regelson, a medical oncologist at Virginia Commonwealth University's medical college, agrees: "If you want to maintain a youthful level of health, then you have to be youthful physiologically and that means maintaining youthful levels of these hormones [DHEA]."

In animal studies, DHEA has been shown to be useful for fighting obesity, diabetes, cancer, autoimmune disease, heart disease, stress, and infectious disease. In other words, it is an all around anti-aging drug. It extends life of laboratory animals by as much as 50 percent. Mice given the hormone look younger and healthier, maintaining the glossiness and coat color of their youth. It may have a life-extending effect in humans as well, although not as great as was originally reported in a study that now spans nearly nineteen years. In 1987, Elizabeth Barrett-Connor and associates at the University of California in San Diego reported a 70 percent drop in mortality from heart disease in men with high DHEA levels. However, a 1995 follow-up study of the same group found only a 20 percent drop in deaths when compared with those who had low DHEA levels. Higher DHEA levels did not protect women at risk of dying from cardiovascular disease.

A 1998 study published in the Journal of the American Geriatric Society found that, out of a group of men between ages sixty and eighty, those with the highest levels of DHEA were younger and leaner, more fit, and had higher testosterone levels than those who were lower in DHEA. However, no such differences were found in women of the same age group between those with the highest and lowest levels of DHEA.