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 CARNITINE INSUFFICIENCY IS ASSOCIATED WITH ADVERSE OUTCOMES IN PATIENTS WITH HEART FAILURE WITH PRESERVED EJECTION FRACTION Cardiac Energy Metabolism in Heart Failure Circulation Research lCarnitine therapy improves right heart dysfunction through Cpt1dependent fatty acid oxidation Agrawal 2022 Pulmonary Circulation Wiley Online Library TMAO: how gut microbiota contributes to heart failure Translational Research L Carnitine 500 mg Carnitine Protocol for Life Balance