About L-carnitine Dietary supplement, Amino acid derivative, Antioxidant. Mechanism of Action of L-carnitine Carnitine is an essential co-factor of fatty acid metabolism in the heart, liver, and skeletal muscle. It is normally synthesised in the liver, brain, and kidneys in sufficient quantities to meet human requirements. It is an antioxidant. It protects neurons from damage caused by super oxide radicals. Indications for L-carnitine 1.As antioxidant 2.Carnitine deficiency