What Is Carnitine and Why Is It Important? The Amino Company Did you know L carnitine, a vital amino acid, is naturally produced by your body and found in various foods? While acetyl L carnitine (ALCAR) can be a beneficial supplement for some, most people get 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 Difference between L Carnitine and L Carnitine L Tartrate