Dehydroepiandrosterone (DHEA), also known as androstenolone or as prasterone (INN), is an endogenous steroid hormone. It is one of the most abundant circulating steroids in humans, in whom it is produced in the adrenal glands, the gonads, and the brain, where it functions 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 and neurotrophin. DHEA is also used orally as a medication and dietary supplement, to restore or increase DHEA and DHEA sulfate (DHEA-S) levels.