Efficacy of a novel formulation of L Carnitine, creatine, and leucine on lean body mass and functional muscle strength in healthy older adults: a randomized, double blind placebo controlled study Nutrition & Metabolism Losing weight with L carnitine supplements. Yes or no? Creatine vs L Carnitine: Benefits and Key Differences Wellversed 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