Dehdydroepiandrosterone (DHEA) is a steroid hormone produced chiefly by the adrenal glands, but it can also be made by the testes, ovaries, and brain. It is the most prevalent adrenal steroid in the body and serves a precursor to the human sex steroids, testosterone and estrogen (see diagram below).  Animal studies have shown the presence of DHEA receptors in tissues such as the kidney, liver, and testes (11).  This might suggest potential functions for DHEA other than simply serving as a hormone precursor. Humans are thought to produce between 1 and 2 mg of DHEA and 10 to 15 mg of DHEAS (the sulfate metabolite) per day (1). DHEAS is formed in the liver  by adding a sulfate(SO4) molecule to it. DHEAS is cleared much more slowly by the kidneys, and blood levels of this metabolite remain much more stable throughout the day. When researchers want to assess blood levels of DHEA, they often measure the sulfate form because of its greater stability.

Orally administered DHEA is usually converted to DHEAS by the intestinal cells.  Bioavailability of PO (by mouth) administered DHEA is very low, with only about 3% of the compound ultimately being available for use by the body (10).  Interestingly, IV (by vein) administration only improves this number to 33%.  The most efficient way to administer DHEA is SC (transdermally).