Carnitine is the generic term for a group of natural substances that include L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine.
Carnitine is found in nearly all cells of the body and in certain foodstuffs, such as meat, fish, poultry, and milk.
Carnitine plays a critical role in energy production. It transports long-chain fatty acids into the mitochondria (the 'power stations' inside the cell) so they can be metabolised to produce energy. It also transports the waste products out of the mitochondria to prevent their accumulation.