Creatine is a nitrogenous compound that acts as a high-energy reservoir for the rapid regeneration of ATP. Approximately 95% of creatine is found in skeletal muscle, primarily as phosphocreatine. Creatine can be acquired through dietary consumption or formed from L-arginine, glycine, and L-methionine in a multi-step reaction that occurs in the kidneys and liver. Creatine is then transported to muscle tissue. Creatine supplementation is used for the enhancement of sports performance, primarily by increasing muscle mass. Creatine is also being investigated as a treatment of neuromuscular diseases, where it may aid in neuroprotection and by improving the cellular bioenergetic state.