L Carnitine Side Effects & Risks L Carnitine Supplement: Heart Concerns Advanced Molecular Labs 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 Deficiency: What Is It, Causes, Symptoms, and More Osmosis L Carnitine Supplementation in the Diabetic Heart ABC Cardiol