Acetyl L-Carnitine is also known as ALCAR, and has been widely popularized as the superior form to L-Carnitine pertaining to the bioavailability. Carnitine is the quaternary ammonium compound which is being used to move fatty acids out of the cytosol and into the mitochondria when the fats are being broken down, when these are needed to generate additional metabolic energy. The biologically active form of Carnitine is L-Carnitine; Acetyl L-Carnitine is the acetylated form of L-Carnitine and is also known as Acetylcarnitine. L-Carnitine is generally derived from lysine and methionine, which are both amino acids. While the neuro-protecting properties of Acetyl L-Carnitine have been tested on lab animals and some proof was obtained, the role of Acetyl L-Carnitine as a weight loss agent still needs some testing in studies on humans.