L-Carnitine is the chief amino acid that helps the body convert fats into energy. It can be stored in many areas like the muscles, heart and brain, but it is manufactured by the kidneys and liver.
Note: Taking D-Carnitine can cause interference with the supplementation of L-Carnitine, which can then cause further problems.
Carnitine is considered conditionally essential, meaning that there are certain conditions a person can undergo which might make supplementation or dietary changes necessary to keep up Carnitine levels. L-Carnitine is necessary for the oxidation of fatty acids, which can eventually aid in fat loss. Fatty acids are one of the main sources of energy for the body and it would be impossible for them to penetrate the cell membrane without the presence of Carnitine.