In the body, one of the most fundamental roles of L- Carnitine is the transport of long chain fatty acids across the mitochondrial membrane into the mitochondria where the fatty acids are ultimately broken down and converted to energy. L-Carnitine is, therefore, essential for fat metabolism and energy production.

Given the ability of L-Carnitine to play a major role in fat metabolism, it is not surprising that one of the first cosmetic applications of this material was in contouring creams and in cellulite control.