Androst-5-ene-3,17-dione
5-androstenedione is a prohormone of testosterone. In the United States, the Controlled Substance Act is inclusive to anabolic steroids and their precursors. Thus 5-androstenedione is a controlled substance, and its use in athletes is prohibited by The World Anti-Doping Agency. Apart from the positioning of a carbon-carbon double bond, its structure is similar to [4-androstenedione], which is a prohormone which is naturally produced in the body by the adrenal glands and gonads, and acts as precursor to testosterone, as well as estrone and estradiol.