L carnitine is effective for both fat loss and athletic performance. However, oral L carnitine has lower bioavailability and can be harmful at high doses, so it should be avoided. , Even cardiologists The Role of l Carnitine in Mitochondria, Prevention of Metabolic Inflexibility and Disease Initiation Codeage Liposomal L Carnitine 500 mg Supplement Free Form Amino Acid 90 Capsules L Carnitine Supplements The bright and the dark sides of L carnitine supplementation: a systematic review Journal of the International Society of Sports Nutrition Springer Nature Link