L-Carnitine is a vitamin-like molecule that serves numerous functions in the body. Its main function is to stimulate the breakdown of fats. L-Carnitine is an alpha-hydroxy acid that is primarily located in the muscle. L-carnitine plays a critical role in the metabolism of fat, contributing to the oxidation of fatty acids and transporting long-chain fatty acids to mitochondria, where they are processed to help provide energy. Muscle needs a regular supply of carnitine to remain toned and healthy. Ultimate Nutrition L-Carnitine Liquid contains 100% USP Quality L-Carnitine.