Drug-Induced Liver Injury Secondary to Enobosarm: A Selective Androgen Receptor Modulator.

Selective androgen receptor modulators (SARMs) are compounds that bind to androgen receptors and have similar anabolic properties to anabolic steroids. Unlike anabolic steroids, which bind to androgen receptors in many tissues all over the body, individual SARMs selectively bind androgen receptors in certain tissues, but not in others. This selectivity has attracted researchers due to the possibility of using SARMs for the potential benefits of androgen receptor stimulation, such as increased muscle mass and increased bone density, while minimizing the adverse effects, such as erythrocytosis and hepatotoxicity. Enobosarm, a SARM, has been studied for use in treatment of cachexia, osteoporosis, breast and prostate cancers, and stress urinary incontinence. Enobosarm can be found in some over-the-counter muscle-building supplements. We report a 31-year-old man with no significant personal or family medical history who presented with itching and dark-colored urine for 1 week. Three weeks prior to presentation, he had begun using a muscle-building supplement containing enobosarm. Diagnostic workup concluded a drug-induced hepatocellular liver injury secondary to enobosarm, which subsequently improved after discontinuation of enobosarm-containing muscle-building supplement use. As enobosarm and other SARMs are increasingly found in the over-the-counter supplements and being studied for other clinical applications, it is important to recognize their potential for liver toxicity.