Nanoparticle mediated L carnitine delivery for improved male fertility ScienceDirect 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 Full article: l Carnitine conjugated chitosan stearic acid polymeric micelles for improving the oral bioavailability of paclitaxel Carnitine: the claims and why it may not work