Creatine is an organic acid that is produced naturally in the body. It is a nitrogenous compound and its primary function is to supply energy to all cells in the body, especially muscle. Since it is produced naturally in the body, it is not an essential nutrient. But for athletics and body trainers or those who have a lot of physical activity to do, it is an essential nutrient. It aids in increasing high-intensity athletic performance. The natural production of Creatine is not enough to provide for the requisite amount for them.

 Source: http://musclemedsrx.com/