L Carnitine is an amino acid found in high concentrations in the heart and liver, which assists with the conversion of fatty acids into energy. Deficiencies in this nutrient may lead to fatigue and muscle weakness. L Carnitine also has antioxidant properties and may help protect the body from free radicals which result from normal body processes, such as the conversion of food into energy, but also from environmental factors such as ultraviolet light, cigarette smoke and pollution. L Carnitine may help neutralize these harmful molecules to stop the chain-reaction of damage they cause.