CARNITOR (levocarnitine) Oral Solution (1 g per 10 mL multidose) 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 Assessing the In Vitro and In Vivo Performance of L Carnitine Loaded Nanoparticles in Combating Obesity Carnitine: Genetic Variants Affecting Mitochondrial Energy and Health