?-Carnitine plays an important role in fatty acid metabolism and has important antioxidant and anti-inflammatory properties. ?-Carnitine is a nonessential amino acid synthesized primarily in the liver and kidneys from the amino acids lysine and methionine. ?-Carnitine is stored in skeletal muscles, brain, heart, and sperm, and therefore plays a functional role in each of these tissues. Deficiency in ?-carnitine may be associated with certain medications, angina, and vegan or vegetarian diets. Symptoms of deficiency may include fatigue, muscle weakness, and a decreased tolerance to metabolic stress.