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 Metabolic therapy for cardiovascular diseases with propionyl L carnitine ScienceDirect TMAO: The Gut Metabolite Linking Red Meat to Cardiovascular Disease Pathobiological Relationship of Excessive Dietary Intake of Choline L Carnitine: A TMAO Precursor Associated Aggravation in Heart Failure in Sarcopenic Patients Amazon.com: Vital Nutrients Carnitine 500mg L Carnitine Supplement for Heart Health Support Vegan Energy Support Supplement Gluten, Dairy, Soy Free Non GMO 60 Capsules : Health & Household JCI l Carnitine in omnivorous diets induces an atherogenic gut microbial pathway in humans