L-carnitine is a very popular supplement that promotes fatty acid metabolism as well as growth and development. L-Carnitine is also used for fat-burning, increasing energy, and improving resistance to muscle fatigue.
Acetyl-L-carnitine is simply an acetylated form of L-carnitine. It is claimed to provide several benefits including life extension.
L-carnitine and Acetyl-L-carnitine supplements are available from A1Supplements.com, as well as from natural and synthetic sources.