Analyses so far have not implicated the substance in those episodes, and no clear evidence of harmful side effects of creatine use has yet emerged elsewhere. Still, as creatine loading has spread from elite settings to high school locker rooms in recent years, questions about safety have been asked more and more often. And as experts await the results of long-term studies, they don't all agree on what to tell patients about creatine use. Creatine, an amino acid, is stored in muscle as phosphocreatine. A half-pound of raw meat contains about 1 g of creatine.
Creatine is available in powders, pills, gum, candy, and liquid.
Interest in creatine supplements has spread beyond the playing field, says Richard B. Kreider, PhD, associate professor and assistant chair in the Department of Human Movement Sciences and Education at the University of Memphis. On the basis of several research studies and his own observations, says Kreider, the effects of creatine supplementation are impressive and occur very fast. At 6 weeks, there's an average 10-lb gain in lean mass. Strength gains are equally dramatic, he says. Not all studies have confirmed the ergogenic effects of creatine supplementation, however.