GLPG0492 is a selective androgen receptor modulator (SARM). It activates the androgen receptor in a transactivation assay (EC50 = 12 nM in HeLa cells expressing the human receptor). GLPG0492 (10 mg/kg per day) increases levator ani muscle weight, a marker of anabolic activity, but has no effect on ventral prostate weight, a marker of androgenic activity, in castrated rats. It increases twitch tension in isolated diaphragm strips, as well as increases the total distance run in a treadmill test and decreases gastrocnemius muscle fibrosis in the exercised-mdx mouse model of muscular dystrophy when administered at a dose of 30 mg/kg. GLPG0492 also reverses immobilization-induced muscle atrophy in a mouse model of hindlimb immobilization.