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 L carnitine is a naturally occurring amino acid structure that is made in the human brain, liver, and kidneys. L carnitine plays a critical role in energy production, as it converts fat into energy. Amazon.com: Life Extension Optimized Carnitine, Three Forms of L carnitine, Promotes Heart & Brain Health, Gluten Free, Non GMO, Vegetarian, 60 Capsules : Health & Household The Brain and Mitochondria Boosting Benefits of Acetyl L Carnitine (ALCAR) by Alex Leaf, M.S. The Energy Blueprint