Taken as directed, creatine phosphate is safe, but it's only effective for a small percentage of athletes. If you're participating in a general exercise program for health, weight management, and cardiovascular health, I wouldn't recommend supplementing with creatine. The substance, which is naturally found in red meat and produced in small quantities by your own body, provides fuel for very short, extremely intense bursts of energy. It plays an important role in the "immediate energy system," the one that powers muscles for the first eight to 15 seconds
Endurance athletes and recreational exercisers have little to no need for supplemental creatine because their workout performance is not limited or enhanced by the amount of energy they can produce with their "immediate energy system." Power athletes, like power lifters, sprinters, and some football players can benefit from the supplement because of the extreme power demands of their sports. However, only some of these athletes see any improvement after taking the supplement, so many who try it end up stopping after a few weeks.