Testolone (RAD-140) is an investigational Selective Androgen Receptor Modulator (SARM). Originally studied for muscle-wasting disorders and hormone-sensitive breast cancer, it is not an approved medication. It is heavily marketed in the black market and bodybuilding communities as an oral performance enhancer. Testolone (RAD-140) is primarily marketed as an alternative to testosterone replacement or anabolic steroids. In the supplement and research chemical industries, it is categorized under specific product tags used for bodybuilding, fitness, and research applications.