Creatine helps the body build up muscle energy. More energy means better muscle contraction. Creatine monohydrate has been studied in boys with Duchenne's muscular dystrophy. The results showed decreased bone breakdown. There may even be some increased bone mineral density when taking this supplement.
In another study creatine upplementation increased handgrip strength in boys with Duchenne's. There's one important finding from these studies. Improvement seems to occur when the body part in question is active. In the study with Duchenne's only the arm strength in the dominant hand improved. Leg strength didn't change in those boys who didn't use their legs.
There are some side effects with creatine use. Weight gain, gas, and bloating are most common. Kidney stones can occur with high doses of creatine. Behavioral changes have also been reported.
No one knows the effect of taking creatine with other drugs or supplements. Check with your doctor before adding any new supplement.