Does creatine affect the kidneys?

In the clinical setting, creatinine levels are measured to assess kidney function. Creatine supplementation raises creatinine levels, although it is completely non-toxic to the kidneys (Robinson, et al 2000). If you are supplementing with creatine and your doctor is running some blood tests, it is imperative that you inform him that you are using creatine otherwise this could give misleading information.