Creatine is a naturally occurring amino acid that helps the body produce energy, especially in muscles. It's found in meat, fish, and animal milk, and the body also produces it in the liver, kidneys, and pancreas.
Creatine is converted into phosphocreatine, or creatine phosphate, and stored in muscles, where it's used as an energy source. During short, intense exercise, like sprinting or weight lifting, phosphocreatine is used to create ATP, which is a major carrier of energy in the body. Creatine also helps muscles flex and contract, which is especially important during exercise.
