Carnitine is a nitrogen-containing compound that assists in fat metabolism. Carnitine plays an essential role in making fatty acids available for muscle tissue. Carnitine is also found naturally in cells which use fat for energy. Carnitine is found throughout the body, including in the heart, muscles, liver and kidney. Carnitine also helps the body use energy stores to power muscular contractions - providing support for endurance exercise and during recovery from high intensity exercise.