Dehydroepiandrosterone/dehydroepiandrostenedione (DHEA, more correctly didehydroepiandrosterone), also known as androstenolone as well as 3ß-hydroxyandrost-5-en-17-one or 5-androsten-3ß-ol-17-one, is an important endogenous steroid hormone. In its pharmaceutical drug form it is called prasterone (INN). It is the most abundant circulating steroid hormone in humans, in whom it is produced in the adrenal glands, the gonads, and the brain, where it functions predominantly as a metabolic intermediate in the biosynthesis of the androgen and estrogen sex steroids. However, DHEA also has a variety of potential biological effects in its own right, binding to an array of nuclear and cell surface receptors, and acting as a neurosteroid.