In active men aged 18–40 undergoing resistance training, both micronized creatine monohydrate (KleanCREATINE™) and a standard marketed creatine monohydrate formulation are safe and well tolerated over eight weeks, with no clinically significant adverse events reported.

Creatine enters muscle cells and pulls water in, making the cells swell. This swelling and the extra creatine help the muscle make energy faster during hard exercise, which keeps the muscle from getting too acidic and tired. Because the muscle doesn't get as tired, the person feels less effort and can keep working harder without harm.