Creatine is a substance that is found naturally in muscle cells. It helps your muscles produce energy during heavy lifting or high-intensity exercise. Taking creatine as a supplement is very popular among athletes and bodybuilders in order to gain muscle, enhance strength and improve exercise performance (1). Chemically speaking, it shares many similarities with amino acids. Your body can produce it from the amino acids glycine and arginine. Several factors affect your body’s creatine stores, including meat intake, exercise, amount of muscle mass and levels of hormones like testosterone and IGF-1 (9). About 95% of your body’s creatine is stored in muscles in the form of phosphocreatine. The other 5% is found in your brain, kidneys and liver (9). When you supplement, you increase your stores of phosphocreatine. This is a form of stored energy in the cells, as it helps your body produce more of a high-energy molecule called ATP. ATP is often called the body’s energy currency. When you have more ATP, your
