Creatine is the safe supplement. Did you know, 90% of the athletes in the world use creatine to boost their performance. Now straight comming to the health concern.

There is some concern that it could harm the kidney, liver, or heart function. However, a connection between high doses and these negative effects has not been proven.Creatine can also cause stomach pain, nausea, diarrhea, and muscle cramping.Creatine causes muscles to draw water from the rest of your body.

But there is no scientific theory proving that creatine is bad for kidneys or liver. A common knock against creatine is that it's bad for the liver, but this doesn't withstand scrutiny. A number of human studies have looked specifically at creatine usage and liver parameters and found no association between the supplement and liver problems.

Looking at the current body of research, it's safe to say:

Creatine does not cause damage to skeletal muscle or the heart, liver, or kidneys.
Creatine, at this moment in time, seems to be fine for kidney disorders that are not characterized by edema and tissue swelling.
Based on limited research, it is probably wise to avoid creatine supplementation if you have polycystic kidney disease, focal segmental glomerulosclerosis, or another kidney disorder characterized by tissue swelling.