Quest Vitamins LTD,
Creatine, a naturally occurring substance, has an important role in the production of energy in humans. It a supplement of choice as a performance enhancer. It is thought that supplemental creatine can build up a reserve of phosphocreatine in the muscles as well as expedite the manufacture by the body of phosphocreatine when it has been used up during athletic performance.
Creatine is used by the body in the energy cycle, combining with Phosphorus to recycle adenosine di-phosphate (ADP) as adenosine tri-phosphate (ATP). 95% is stored within the muscle cells.
Some formulations can lead to gastrointestinal upsets and the long-term safety has not been determined.
Individuals with kidney disease should avoid creatine, especially if undergoing dialysis.
Caffeine appears to block the effect of creatine (3).
1. Earnest CP et al: The effect of creatine monohydrate ingestion on anaerobic power indices, muscular strength and body composition. Acta Physiol Scand 1995 Feb; 153(2):207-9.