Hydroxy linoleins are a mixture of 132 possible isomers of mono-, di-, and tri-hydroxy compounds produced by the autoxidation of trilinolein and subsequent reduction of the hydroperoxides. Autoxidation of linoleic acid containing triglycerides (i.e., trilinolein) in vivo could result in the formation of hydroperoxides, which could then be reduced by peroxidases to produce hydroxy linoleins. Due to their inherent stability compared to the precursor hydroperoxides, hydroxy linoleins are potential markers of triglyceride lipid peroxidation in vivo.