What is L Carnitine? L Carnitine is a naturally occurring amino acid derivative that the human body can synthesize itself. It is mainly found in red meat and dairy products. [1] Core Benefits of Benefits of Acetyl L Carnitine Simply Supplements Acetyl L Carnitine Vegetarian Capsules Natural Factors USA Should I Take Acetyl L Carnitine or L Carnitine HealthAid Acetyl L Carnitine Tablets NOW Foods CarniBlast Liquid L Carnitine 3000mg Energy Supplement Bricker Labs