DHEA is the most prevalent of the hormones produced by the adrenal glands. After being secreted by the adrenal glands, it circulates in the bloodstream as DHEA-sulfate (DHEAS) and is converted as needed into other hormones. Supplementation with DHEAS has resulted in increased levels of testosterone and androstenedione, two steroid hormones.

The conversion of DHEA into testosterone may account for the fact that low blood levels of DHEA have been reported in some men with erectile dysfunction. The findings of a double-blind trial using 50 mg supplements of DHEA taken daily for six months suggests that DHEA may improve erectile function in some men.

Some, but not all, clinical trials have found that DHEA supplementation lowers fat mass without reducing total body weight. In one trial, the reduction in fat mass occurred in men but not in women.

DHEA is believed to indirectly affect blood sugar levels, but information remains incomplete and contradictory. Attempts to affect blood sugar levels in humans have led to improvements, no effect, and, at very high amounts (1,600 mg DHEA per day), a worsening of tolerance to sugar.

DHEA modulates immunity. A group of elderly men with low DHEA levels who were given 50 mg of DHEA per day for 20 weeks, experienced a significant activation of immune function. Postmenopausal women have also shown increased immune functioning in just three weeks when given DHEA in double-blind research.

Some reports have suggested that DHEA might reduce the risk of heart disease, perhaps by lowering cholesterol levels. DHEA may also be a blood thinner, an effect that in theory should help protect against heart disease. However, most research supports the idea that DHEA protects against heart disease only weakly for men, and not at all for women.In fact, higher levels of DHEA and DHEAS have been associated with cardiovascular risk factors in women, including high blood pressure and smoking.Moreover, DHEA has also been reported to lower HDL (the “good” cholesterol). Until more is known, DHEA should not be used to protect against heart disease.

Claims have appeared that DHEA is an anti-aging hormone. However, the fact that young people have higher levels of DHEA than older people does not necessarily mean that supplementing DHEA will make people younger. In some, but not all,double-blind trials, DHEA has improved the sense of well being in elderly individuals. In one double-blind trial, DHEA supplementation did appear to reduce some of the adverse effects of aging, though it did not create “supermen/superwomen.” In that trial, healthy elderly women and men were given either 50 mg of DHEA or a placebo daily for one year. In addition to a re-establishment of more youthful levels of DHEAS, slight increases were also observed in other hormones, such as testosterone and estrogens. In women over 70 year of age, bone mineral loss was improved. A significant increase in most measures of libido was also seen in these older women. Improvements of the skin were also observed in both women and men, but particularly in women, in terms of hydration, thickness, pigmentation and production of sebum (oily secretion that lubricates the skin and hair).

Systemic lupus erythematosus (SLE), an autoimmune disease, has been linked to abnormalities in sex hormone metabolism. Supplementation with very large amounts of DHEA (200 mg per day) improved clinical status and reduced the number of exacerbations of SLE in a double-blind trial. A preliminary trial has confirmed the benefit of 50–200 mg per day of DHEA for people with SLE.

DHEA may play some role in protecting against depression. Low DHEA levels have been reported in older women suffering from this condition, though at least one report has linked severe depression to increased DHEA levels. After six months using 50 mg DHEA per day, “a remarkable increase in perceived physical and psychological well-being” was reported in both men and women in one double-blind trial. In another double-blind trial, after only six weeks of taking DHEA at levels up to 90 mg per day, at least a 50% reduction in depression was seen in five of eleven patients. Other researchers have reported dramatic reductions in depression at extremely high amounts of DHEA (90–450 mg per day) given for six weeks to adults who first became depressed after age 40 (in men) or at the time of menopause (in women) in a double-blind trial.Limiting supplementation to only two weeks is inadequate in treating people with depression.

Despite the dramatic results reported in trials lasting at least six weeks, some experts claim that in clinical practice, DHEA appears to be effective for only a minority of depressed people. Moreover, due to fears of potential side effects, most healthcare professionals remain concerned about the use of DHEA. As with other uses of DHEA, depressed people should not take this hormone without supervision from a healthcare professional.