L Carnitine Benefits: A Complete Research Based Guide Levocarnitine, commonly known as L Carnitine, is a naturally occurring compound that the body produces from the amino acids lysine and methionine. It plays a critical role in energy production by transporting fatty Carnitine traffic and human fertility ScienceDirect Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis L Carnitine and Male Fertility: Is Supplementation Beneficial?