L Carnitine Benefits, Uses, Dosage, Foods, Side Effects Dr. Axe 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. The Role of l Carnitine in Mitochondria, Prevention of Metabolic Inflexibility and Disease Initiation L Carnitine for Fat Burning: How It Really Works (Without the Hype) Is L Carnitine the Key to Fat Loss? Protyze