Lipid peroxidation is a key factor in programmed cell death of various etiologies. This process also occurs when ionizing radiation acts on biological systems. It is the essence of the theory of lipid radiotoxins, which is part of the structural and metabolic theory of the biological action of ionizing radiation. Non-enzymatic lipid peroxidation eventually leads to death by the mechanism of ferroptosis, while enzymatic lipid peroxidation, catalyzed by the cytochrome c-cardiolipin complex, triggers apoptosis along the mitochondrial pathway.