MK-2866 (Ostarine) is a selective androgen receptor modulator studied for its potential influence on lean muscle preservation, strength, and physical function. Research has explored its selective activity within muscle and bone tissues, including investigations involving muscle loss and body composition. Its tissue-focused mechanism has generated scientific interest in lean mass maintenance, recovery-related pathways, and functional performance. MK-2866 continues to be examined for its potential role in supporting musculoskeletal research and broader performance-related physiological outcomes under controlled conditions.