RAD140, also known as Testolone is often referred to as the most powerful SARM. It is still being researched by a pharmaceutical company called Radius Health. Selective Androgen Receptor Modulators (SARMs) are what most consider to be safe alternatives to steroids.
Upon oral administration, SARM RAD140 acts as an agonist in select tissues, such as skeletal muscle and bone, where it binds to and activates androgen receptors (ARs). In the prostate and breasts, RAD140 acts as an antagonist and blocks AR activation and AR-mediated cellular proliferation. Therefore, this agent may improve bone formation and muscle mass and strength, and may inhibit both the growth of the prostate in males and AR-dependent breast cancer cell proliferation. Compared to anabolic agents, SARMs have reduced androgenic properties.