Liquid L Carnitine Citrus Swanson Vitamins 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 Foods High in L Carnitine for Energy and Health Marnys L Carnitine (tartrate) Levocarnitine, commonly known as L Carnitine, is a naturally occurring compound that the body produces from the amino acids lysine and methionine. It plays a critical role in energy production by transporting fatty