There is no scientific evidence to prove that long-term creatine supplementation may lead to any potential harm to the body. The international society of sports recently conducted a study to find out if long-term creatine intake had any side effects on the body; over a period of 21 months two groups of athletes (one group was supplemented with creatine and rest were given no supplements) were rigorously tested and their urine and blood samples were carefully studied to observe their heart and renal function.