L Carnitine Vitamin Supplement for Energy and Metabolism Boost Acetyl L Carnitine is more thought of as a fat burner. It's actually powerful tool for athletes looking to improve endurance, energy, and mental performance. Here's how you can integrate it into your routine for Amazon.com: NOW Foods Supplements, Acetyl L Carnitine 500 mg, Amino Acid, Brain And Nerve Cell Function*, 50 Veg Capsules : Health & Household Acetyl L Carnitine vs L Carnitine: 4 Key Differences Momentous