L-Carnitine is a nutrient that is derived from the amino acids lysine and methionine. Its name is derived from the fact that it was first isolated from meat (carnus). L-Carnitine is not considered a dietary essential because it is synthesized in the body. The body produces carnitine in the liver and kidneys and stores it in the skeletal muscles, heart, brain, and other tissues. But its production may not meet the needs under certain conditions such as increased energy demands and therefore it is considered a onditionally essential nutriention. There are two forms (isomers) of carnitine, viz. L-carnitine and D-carnitine, and only the L-isomer is biologically active.