LGD-4033 is a selective androgen receptor modulator a novel non-steroidal, oral SARM that binds to AR with high affinity (Ki of ~1 nM) and selectivity, class of androgen receptor (AR) ligands that is tissue selective, developed totreat muscle wasting associated with cancer, acute and chronic illness and age-related muscle loss.

LGD4033 works by tying androgen receptors selectively. It shows anabolic activity in the bones and muscles instead of harmfully affecting the prostate and sebaceous glands which usually happens when using steroids. LGD-4033 just concluded a study called Phase I Multiple Ascending Dose which included fit volunteers. This was an unplanned, double bind analysis stage that included a placebo. The objective was to form that using LGD-4033 was harmless and easy to stomach with a dose not beyond 22 mg a day.