DHEA is a steroid hormone naturally produced in the brain and the adrenal glands, and is also contained in soy and wild yams. However, the hormonal ingredients in yams and soy cannot be converted into DHEA in the body, according to MedlinePlus. DHEA, or dehydroepiandrosterone -- also known as prasterone -- is secreted in the testes in men as well. The hormone converts in the body to androstenedione, which then converts into male and the sex hormones androgen and estrogen.
DHEA affects memory and thinking, especially in the elderly whose levels often fall to as much as 80 percent below DHEA levels in young adults, according to the University of Maryland Medical Center, or UMMC. DHEA can be taken as a dietary supplement for a variety of reasons: to increase muscle mass and endurance, treat erectile dysfunction in men and improve libido in women. DHEA is also used for a wide range of medical conditions, including multiple sclerosis, osteoporosis and Parkinson's disease. The UMMC adds that synthetic versions of the hormone are used treat HIV symptoms, and that menopausal women can use it to strengthen vaginal walls.
According to MedlinePlus, as of 2010, DHEA supplements are being investigated by the Food and Drug Administration as a treatment for lupus and bone loss, and that the supplements may be approved when the studies are complete. MedlinePlus adds that DHEA has proven to be effective for treating women with depression, improving sexual functioning in men, strengthening the skin in older people and decreasing the instances of liver, or age, spots in the elderly.
The production of DHEA decreases with age, which is why dietary supplements of the hormone may be more worthwhile for older people to take. DHEA levels also decrease in people suffering from depression. According to the UMMC, the optimum levels of DHEA are 180 milligrams per deciliters of blood, or mg/dl, for men; women's optimum DHEA levels should be about 130 mg/dl. The UMMC recommends 50 mg of DHEA per day for men and 25 mg per day for women, though it does not recommend supplemental DHEA for those under 40 years old. Women with anorexia may benefit from higher doses.
Side effects of DHEA can be dangerous to unborn children, so pregnant women should not take the supplement. Drug interactions with insulin are possible, so diabetics should avoid the drug as well. The hormone can interrupt cancer treatments and may lower good cholesterol numbers; it can create additional symptoms in people with mood disorders. Long-term use of DHEA can cause additional side effects such as acne, changes in the menstrual cycle and facial hair growth in women. The UMMC addds that DHEA can lead to high blood pressure and heart arrhythmias as well.
Manufacturers of DHEA are not regulated by a government agency, so take precautions when purchasing the dietary supplements. Most DHEA products are made by synthesizing wild yams, even though wild yams alone cannot produce the hormone. According to MayoClinic.com, any marketing that claims to contain natural DHEA is false. To make sure you are getting a quality product, MedlinePlus recommends purchasing the supplements from a reputable dealer or a health care provider.