The results on tests of athletes that have used creatine for up to three continuous years show this supplement causes no detrimental effects to the liver or kidneys. That’s the conclusion of a long-term study performed at Truman State University in Kirksville, Missouri.
Researchers at Truman State examined the effect of long-term creatine supplementation on the liver and kidney function of collegiate football players. Creatine supplementation was undertaken for an average of 2.9 +/- 1.8 years with supplementation dosages that ranged from 5 to 20-grams per day. When venous blood samples were compared between the creatine treatment and control groups, there were no differences found in any of the clinical markers typically used to determine impairments in liver and kidney function. Additionally, all measures determined for the creatine group fell within clinically normal ranges.
Contrary to what most uninformed journalists write, research shows creatine supplementation is both very safe and very effective.
Source: International Journal of Sport Nutrition and Exercise Metabolism