Healthy Options L Carnitine 500mg 30 Capsules What is L Carnitine? Wait, what is an Amino Acid? by Medium 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 Amazon.com: NOW Foods Supplements, L Carnitine 1,000 mg, Purest Form, Amino Acid, Fitness Support*, 100 Tablets : Health & Household L Carnitine, 500 mg, 60 Vegetarian Capsules