RAD-140 or Testolone, is a powerful orally active anabolic in a group of chemicals known as SARMS (Selective Androgen Receptor Modulators). RAD-140 appears to have a high selectivity for targeting bone and lean muscle tissue over other tissues such as organs. Although it does appear to activate androgens outside of these tissues, it is comparatively less than with anabolic steroids or natural testosterone. Testolone has an anabolic androgenic binding ratio of 20 to 1; the powerful SARM, LGD-4033, has a ratio of 10:1.