Side effects
There are claims that creatine users are more susceptible to cramps, muscle spasms, and even pulled muscles. However, three-years of creatine supplementation had no effect on the incidence of injury or cramping in college American footballers.
Research published in the journal Medicine and Science in Sports and Exercise shows similar results [35]. In a group of 26 athletes (18 men and 8 women) using creatine for up to four years, there was no difference in the reported incidence of muscle cramp or injury compared with athletes not using creatine.
A more recent study, published in the September 2004 issue of the International Journal of Sports Medicine, also shows that creatine side effects are rare .
A group of 175 subjects received either 10 grams of creatine or placebo daily for an average period of 310 days. Diarrhea and nausea did cause three subjects to stop using creatine. But there were no other significant differences between the groups.
Researchers from Truman State University also report that long-term creatine use appears to be safe .
Twenty-three members of an NCAA Division II American football team were divided into a creatine group and a control group who took no supplements.
Subjects in the creatine group averaged 14 grams of creatine a day for three years. However, the researchers could find no detrimental effects on either kidney or liver function.
There are isolated case reports of individuals suffering adverse effects after using creatine. Yet, carefully controlled studies over the short- (five days), medium- (nine weeks) and long-term (up to five years) have yet to demonstrate that creatine supplementation has any adverse effects on blood pressure, kidney or liver function .
Studies focusing on the medical applications of creatine using continuous low doses (less than two grams per day) for up to five years show no adverse side effects. Of course, an absence of evidence is not evidence of absence. The fact no side effects have been found doesn't mean none exist. People with existing liver or kidney problems, or those predisposed to such ailments, should seek medical advice before using creatine .
