L Carnitine vs L Arginine: Understanding Their Differences and Benefit Fitness Health Does L Carnitine Really Work? An Honest Guide The Science of Good Health Ever heard of Acetyl L Carnitine? This amino acid is found in nearly all cells of the body. L Carnitine contributes to the production of energy from long chain fatty acids. And, it increases the activity L Carnitine Vitamin Supplement for Energy and Metabolism Boost