Δ⁵-Androstenedione is a prohormone of testosterone. The World Anti-Doping Agency prohibits its use in athletes. In the United States, it is a controlled substance. Δ⁵-Androstenedione is structurally similar to Δ⁴-androstenedione, with the exception of the position of a carbon-carbon double bond. Δ⁴-Androstenedione is naturally produced in the body by the adrenal glands and gonads. In addition to testosterone, it is also a precursor of estrone and estradiol.