DHEA is a natural steroid hormone that is synthesized from cholesterol through pregnenolone by the adrenal glands. DHEA acts as the parent precursor for other important steroid hormones, such as estradiol and other estrogens, and testosterone. While not a precursor to progesterone, DHEA made by the body can indirectly influence progesterone synthesis through a feedback mechanism whereby pregnenolone is converted to progesterone based on DHEA levels. Apart from these functions, DHEA also has important biological functions itself. Recent experimental and human studies show that DHEA is involved in supporting a large variety of physiological processes including immune function, brain function, bone metabolism, and the regulation of
insulin-like growth factor levels.