Creatine is a natural acid produced in kidney and liver and mostly stored in the muscle cells but it can also be supplied by nutrition. Tissues with high energy demands take up Creatine through an active transport system.
Muscle cells use CreatinePhosphate, a phosphorylated form of Creatine, to store energy. In the human hair follicle, the Creatine active transport system and the Creatine kinase (enzyme) are responsible for the energy production.