Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis 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 What Is CoQ10 and L Carnitine, and How Can It Change Your Life? iThrive Essentials Did you know L carnitine, a vital amino acid, is naturally produced by your body and found in various foods? While acetyl L carnitine (ALCAR) can be a beneficial supplement for some, most people get Is L Carnitine safe for athletes at doses up to 6000 mg day? Consensus