L carnitine is primarily synthesized in the liver from the amino acids lysine and methionine through a series of four enzymatic reactions, with the liver and kidneys converting the precursor butyrobetaine into active Some supplements may cause liver damage L carnitine promotes liver regeneration after hepatectomy by enhancing lipid metabolism Journal of Translational Medicine Springer Nature Link L carnitine tartrate supplementation in the fight against infectious disease L carnitine supplementation in non alcoholic fatty liver disease: A systematic review and meta analysis