Purity >95%. Ferroptosis is a regulated, non-apoptotic form of cell death involving the production of iron-dependent reactive oxygen species (ROS). Glutathione peroxidase 4 (Gpx4) is an essential regulator of ferroptotic cell death, playing a critical role in preventing ROS-induced lipid peroxidation. Liproxstatin-1 is an inhibitor of ferroptosis induced in mouse embryonic fibroblasts (MEFs) by Gpx4 deletion (IC50 = 22 nM). It does not interfere with apoptosis, necroptosis, or necrosis. Liproxstatin-1 also blocks ferroptosis induced by specific ferroptosis inducers, including the glutathioine-depleting agents BSO and erastin and the Gpx4 inhibitor RSL3. It is effective in vivo when administered intraperitoneally, suppressing ferroptosis in Gpx4-/- mice and in a mouse model of ischemia/reperfusion-induced liver injury.