It is one of the hottest supplements on the market, seems to have few negative side effects, and works to mimic naturally occurring substances that are related to fitness. Creatine itself is normally manufactured from 3 different amino acids by the liver, kidneys and pancreas and released to the muscles via the bloodstream, where it operates in the muscles as an energy source. There appears to be little downside when taken in appropriate doses. At excessive levels, though, it may contribute to dehydration, muscle and ligament tears, diarrhea and possibly kidney failure. But overall, the research as well as anecdotal evidence would show that it is relatively safe with few if any long-term negative effects.
Creatine allows one to work out harder and recover faster.
The greater intensity of the workout allows one to build more muscle mass. Some information about Creatine as well as links to other sources can be found here. Absolute Creatine Creatine Pyruvate is a chemical combination of pyruvate and creatine. The hype is that these compounds accelerated fat loss without sacrificing lean muscle mass and add endurance during intense exercise. More glucose within the muscle cell leads to greater glucose utilization and glycogen buildup and retention.