Creatine is a chemical compound of carbon and nitrogen. Our body can only produce it - it is synthesized in the liver, pancreas, and kidneys. Creatine itself is not an energy source but plays a crucial role in energy metabolism in muscles as it promotes the synthesis of ATP, the energy source for muscles. It directly contributes to increasing muscle mass and strength, but only in combination with physical activity. The best results are seen in bodybuilders, as creatine stimulates muscle growth and strength gains.