What is L-carnitine fumarate?L-carnitine fumarate is a stable form of the amino acid, L-carnitine. L-carnitine is found abundantly in heart muscle and skeletal tissue. It functions primarily as a shuttle for fatty acids, transporting them across mitochondrial membranes into the mitochondria, where they are used for energy production. L-carnitine has been used to enhance exercise recovery and maintain …