L carnitine is an amino acid that is produced in your body that helps the body turn fat into energy. Carnitine is found in nearly all cells of the body and researchers have Meet L Carnitine a naturally occurring amino acid that plays a key role in helping the body convert fat into usable energy. It works by transporting fatty acids into your cells to L CARNITINE (LEVOCARNITINE) What is it? L Carnitine is a natural amino acid that helps the body turn fat into energy. How it works: Levocarnitine forces fat into the cells to L Carnitine Linus Pauling Institute Oregon State University