Creatine is an amino acid found primarily in your muscles, but it is also found in your brain. Your body's liver, pancreas, and kidneys can make creatine. You can supplement creatine by consuming foods like seafood and red meat.

Creatine is an amino acid found primarily in the muscles and brain. Although it can be synthesized, most people get creatine from seafood and red meat. The body converts creatine into phosphocreatine and stores it in the muscles, where it is used for energy. Therefore, people take creatine supplements orally to improve athletic performance and increase muscle mass.