L-Lysine-d₃is intended for use as an internal standard for the quantification of L-lysine by GC- or LC-MS. L-Lysine is an essential amino acid.¹It is catabolizedviathe saccharopine pathway to produce acetyl-coenzyme A in liver mitochondria. L-Lysine is also a precursor in the biosynthesis of L-carnitine , a conditionally essential nutrient that has roles in energy production and fatty acid metabolism.²L-Lysine (400 mg/kg per day) reduces viral shedding in cats latently infected with feline herpesvirus type 1 (FHV-1).³Administration of an L-lysine-deficient diet increases fecal pellet excretion induced by restraint stress, indicating increases in anxiety, in rats.⁴Formulations containing L-lysine have been used as dietary supplements.

1.Leandro, J., and Houten, S.M.Saccharopine, a lysine degradation intermediate, is a mitochondrial toxinJ. Cell Biol.218(2)391-392(2019) 2.Flanagan, J.L., Simmons, P.A., Vehige, J., et al.Role of carnitine in diseaseNutr. Metab.7(30)(2010) 3.Maggs, D.J., Nasisse, M.P., and Kass, P.H.Efficacy of oral supplementation with L-lysine in cats latently infected with feline herpesvirusAm. J. Vet. Res.64(1)37-42(2003) 4.Smriga, M., Kameishi, M., Uneyama, H., et al.Dietary •-lysine deficiency increases stress-induced anxiety and fecal excretion in ratsJ. Nutr.132(12)3744-3746(2002)