Targeting Skeletal Muscle Dysfunction With L Carnitine for the Treatment of Patients With Chronic Obstructive Pulmonary Disease In Vivo 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 The Role of L Carnitine in Kidney Disease and Related Metabolic Dysfunctions The Science of Carnitine: How It Works and Why It Matters