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 What is L Carnitine, L Carnitine is an amino acid that plays a role in energy production and fat metabolism. Its found in foods like red meat, fish, and dairy, and also available as a supplement., Pharmacokinetics of L Carnitine Clinical Pharmacokinetics Springer Nature Link JCI l Carnitine in omnivorous diets induces an atherogenic gut microbial pathway in humans