4-hydroxy Nonenal-d3 (4-HNF-d3) contains three deuterium atoms at the terminal methyl position. It is intended for use as an internal standard for the quantification of 4-HNE by GC- or LC-mass spectrometry. 4-HNE is a lipid peroxidation product derived from oxidized ω-6 polyunsaturated fatty acids such as arachidonic acid. 4-HNE is widely used as a marker of lipid peroxidation. It exhibits various biological activities such as cytotoxicity, growth inhibiting activity, genotoxicity, and chemotactic activity. 4-HNE inhibits pro-oxidant-induced Ca2+ release from mitochondria at 10-50 μM.