The amino acid, l-Carnitine is required by the body to make protein. Synthesized by the liver and kidneys, l-Carnitine is required for fatty acids to be delivered into cells and burned as energy. Considered the fat-burning amino acid, l-Carnitine continuously works to rebuild body tissue, metabolize fatty acids and stimulate muscle growth. L-Carnitine also enhances the properties of antioxidants such as vitamin C and vitamin E. The liver needs sufficient amounts of vitamin C, Vitamin B6, thiamine and l-lysine to naturally produce l-Carnitine. Other natural sources for l-Carnitine include avocados, dairy products, red meats and tempeh. L-Carnitine is considered a good ingredient for overall health and cardiovascular function.