International Society of Sports Nutrition position stand: creatine supplementation and exercise.
J Int Soc Sports Nutr. 2007 Aug 30;4(1):6 [Epub ahead of print]

ABSTRACT: Introduction (this article has no abstract) The use of creatine as a sport supplement has been surrounded by both controversy and fallacy since it gained widespread popularity in the early 1990's. Anecdotal and media reports have often claimed that creatine usage is a dangerous and unnecessary practice; often linking creatine use to anabolic steroid abuse. Many athletes and experts in the field have reported that creatine supplementation is not only beneficial for athletic performance and various medical conditions but is also clinically safe. Although creatine has recently been accepted as a safe and useful ergogenic aid, several myths have been purported about creatine supplementation which include: 1. All weight gained during supplementation is due to water retention. 2. Creatine supplementation causes renal distress. 3. Creatine supplementation causes cramping, dehydration, and/or altered electrolyte status. 4. Long-term effects of creatine supplementation are completely unknown. 5. Newer creatine formulations are more beneficial than creatine monohydrate and cause fewer side effects. 6. It's unethical and/or illegal to use creatine supplements. While these myths have been refuted through scientific investigation, the general public is still primarily exposed to the mass media which may or may not have accurate information. Due to this confounding information, combined with the fact that creatine has become one of the most popular nutritional supplements on the market, it is important to examine the primary literature on supplemental creatine ingestion in humans. The purpose of this review is to determine the present state of knowledge concerning creatine supplementation, so that reasonable guidelines may be established and unfounded fears diminished in regard to its use.