L Lysine Supplements, L carnitine, Essential Amino Acid, Acetyl Coenzyme A Tasman Health New Zealand Source Naturals L Proline L Lysine, 275 mg 120 Tablets Smith's Food and Drug The Role of l Carnitine in Mitochondria, Prevention of Metabolic Inflexibility and Disease Initiation Bottomline: L Carnitine is a naturally occurring amino acid derivative synthesized in the body from lysine and methionine. It's essential for energy metabolism, primarily by transporting long chain fatty acids into the mitochondria of L Carnitine plays an important role in the larger metabolism equation: helping your body use fat efficiently as fuel. Learn more about the science on this week's post on The Wellness Edit.