L Carnitine for Fat Burning: How It Really Works (Without the Hype) Is L Carnitine the Key to Fat Loss? Protyze L carnitine is a naturally occurring amino acid structure that is made in the human brain, liver, and kidneys. L carnitine plays a critical role in energy production, as it converts fat into energy. L Carnitine functions as a cofactor for long chain fatty acids across Download Scientific Diagram Carnitine: the claims and why it may not work Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis