High l Carnitine Ingestion Impairs Liver Function by Disordering Gut Bacteria Composition in Mice Journal of Agricultural and Food Chemistry 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 3 Ways to Give LCarnitine to Cats with Fatty Liver wikiHow Pet The Importance of the Fatty Acid Transporter L Carnitine in Non Alcoholic Fatty Liver Disease (NAFLD)