L Carnitine Liquid Benefits Explained: A Guide The Science of Good Health Nutrient Tip Tuesday: Meet the Fat Burning Powerhouse: L Carnitine This essential nutrient acts as a shuttle, transporting fatty acids directly into your mitochondria to be burned for ATP (energy). Essentially, it helps your L Carnitine is an amino acid found in high concentrations in muscle, heart, and liver tissues. Inside the cells, L Carnitine transports fatty acids into the mitochondria for energy production (i.e., ATP) and reduces Carnitine: Genetic Variants Affecting Mitochondrial Energy and Health