Creatine
A naturally-occurring, nitrogenous compound that – in the form of creatine phosphate – functions as a phosphagen: a storage form of phosphate for the production of ATP. Creatine can be consumed in the diet from animal protein, derived from the amino acids arginine, glycine and methionine, or taken in supplemental form.
Creatine supplements are taken by bodybuilders and other strength athletes to enhance lean body mass and strength. Creatine also has therapeutic potential, and has been used experimentally to treat neuromuscular disorders.
See also: Creatine Monohydrate.