http://advicentips.co.uk/recommends/creatinemusclebuilder Creatine (Cr) is a naturally occurring amino acid found in muscle tissue of humans and animals. It plays an important role in fueling muscles. The human body has 100 to 115 grams of creatine stored in the form of creatine phosphate or phosphocreatine. Approximately 95% of the body’s creatine supply are found in the skeletal muscles. The remaining 5% are scattered throughout the rest of the body, with the highest concentrations in the heart, brain and testes. Creatine is easily absorbed from the intestinal tract into the bloodstream. When dietary consumption is inadequate to meet the body’s needs, a limited supply can be synthesized from the amino acids arginine, glycine and methionine. This creatine production occurs in the liver, pancreas and kidneys. Creatine also adds water to your muscles, which helps them recover quicker and allows you to workout longer, it also reduces the effects of muscle atrophy if a limb is immobilised for a period of time..