Ostarine, also known as MK-2866 is a SARM (selective androgen receptor module) created by GTx to avoid and treat muscle wasting. It can later on be a cure for avoiding atrophy (total wasting away of a body part), cachexia, sarcopenia and Hormone or Testosterone Replacement Therapy. This type of SARM cannot only retain lean body mass but as well as increase it. Ostarine is often mistaken as S1 but S1 was created earlier and is no longer going through more expansion.