It will depend on the individual, the type of creatine used, and how much creatine used daily. I used to have bloods done weekly, and did nor have ANY issues with any creatine re kidneys, etc. unless it was creatine ethyl ester - and I will never use that again. Again, everyone must do what is right for them, and if one knows their body, then they can make the best decision on what to do.
~Rosie
Team APPNUT