Anabolic steroids are synthetic derivatives of testosterone shown to increase muscle size and strength. Chemical substitutions on the testosterone molecule cause increased potency and duration of action. The 17-α-alkylation modification allows steroids to be taken orally, but the slower clearance in the liver makes them more hepatotoxic. The frequency and severity of side effects depends on several factors including the formulation of the drug, route of administration, dosage, duration of use, and individual sensitivity and response. Anabolic steroid users tend to take supraphysiologic doses or multiple steroids and other drugs simultaneously which increases risk of adverse effects. Hepatotoxicity can be seen as elevated liver transaminases, acute cholestatic syndrome, chronic vascular injury, hepatic tumors, and toxicant-associated fatty liver disease, as well as significant changes in lipoproteins. Many of these changes will stabilize or reverse with cessation of steroid use, but some can be life-threatening. Over-the-counter supplements can be contaminated with anabolic steroids, causing hepatotoxicity in unsuspecting consumers.