The Right Way to Take L Carnitine to Boost Your Training 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 Beneficial effects of l carnitine supplementation for weight management in overweight and obese adults: An updated systematic review and dose response meta analysis of randomized controlled trials ScienceDirect Amazon.com: NOW Foods Supplements, L Carnitine 1,000 mg, Purest Form, Amino Acid, Fitness Support*, 100 Tablets : Health & Household Does L Carnitine Work For Fat Loss?