L Carnitine Benefits: A Complete Research Based Guide Ingredient Spotlight: L Carnitine Source: Biosynthesised in the body from the amino acids Lysine and Methionine, L Carnitine is a conditionally essential nutrient involved in energy metabolism and fat transport. Key Benefits L carnitine known as the energy nutrients, provides massive benefits to your heart and works best with Alpha Lipoic Acid. Foods High in L Carnitine for Energy and Health Marnys L Carnitine Pure Powder, 3 oz. NOW Foods Fruitful Yield