A ferroptosis inhibitor; inhibits ferroptotic cell death (IC50 = 22 nM) and lipid peroxidation in inducible Gpx4-/- MEFs at 50 nM; inhibits ferroptosis induced by the ferroptosis-inducing agents BSO, erastin, and (1S,3R)-RSL3 in a concentration-dependent manner in MEFs; inhibits cell death and lipid peroxidation induced by (1S,3R)-RSL3 in human renal proximal tubule epithelial cells; increases survival and decreases TUNEL+ kidney cells in inducible Gpx4-/- mice at 10 mg/kg; reduces tissue injury in a mouse model of hepatic ischemia/reperfusion injury; an antioxidant that inhibits autooxidation of lipids by trapping peroxyl radicals