L Carnitine For Weight Loss Know Its Benefits And Sources What Foods Are High in Carnitine? Deficiency Side Effects 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 L carnitine known as the energy nutrients, provides massive benefits to your heart and works best with Alpha Lipoic Acid.