Hi, Thanks for writing to HCM. Creatine a popular substances which would enhance muscle mass. Although creatine is a natural substance, the effects it would cause by its consumption over the long-term hasn t been studied well. Researchers still aren t sure what effects it might have or how effective it is on the body, particularly in young people. Side effects it can cause and need to be watchful include: Weight gain, Breathing difficulty, Fatigue, Nausea, vomiting, Diarrhea, Headache and Kidney problems. Hence, it is advisable to use it only when it is required. Hope the information provided would be useful. All the best.