All You Need To Know About L Carnitine HealthKart Amazon.com: Source Naturals L Carnitine, Metabolic Energy*, 250mg 120 Capsules : Health & Household Benefits of Acetyl L Carnitine Simply Supplements 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 L carnitine known as the energy nutrients, provides massive benefits to your heart and works best with Alpha Lipoic Acid.