From the Research
Taking creatine supplements can increase blood creatinine levels, but this elevation does not necessarily indicate impaired renal function. According to the most recent and highest quality study, creatine supplementation may increase serum creatinine concentration for some individuals, but it does not necessarily indicate kidney dysfunction, as creatine is spontaneously converted into creatinine 1. The study found that creatine supplements have been shown to be safe for human consumption, and further studies with people who have pre-existing kidney disease remain necessary.
Key Points
- Creatine is converted to creatinine in the body as part of normal metabolism, so when you consume additional creatine through supplements, your blood creatinine levels may rise.
- This elevation is not harmful but represents a normal physiological response to increased creatine intake.
- The effect is particularly noticeable during the loading phase of creatine supplementation when higher doses are sometimes taken.
- The elevated creatinine from creatine supplementation does not indicate kidney damage or dysfunction; it simply reflects the increased creatine-creatinine conversion occurring in your body due to the higher creatine availability from supplements.
Recommendations
- If you're taking creatine supplements, it's essential to inform your healthcare provider before any blood tests measuring kidney function.
- Creatine supplementation appears to be safe when used by healthy adults at the recommended loading and maintenance doses, but it may be associated with an increased risk of renal dysfunction in people with a history of renal disease or those taking nephrotoxic medications 2, 3, 4.
- The safety of creatine in children and adolescents has not been established, and future studies should include renal function markers other than serum creatinine and creatinine clearance 2.
Evidence Summary
The most recent study found that creatine supplementation did not significantly alter serum creatinine levels, and did not alter plasma urea values, indicating that creatine supplementation does not induce renal damage in the studied amounts and durations 5. Overall, the evidence suggests that creatine supplements are safe and do not cause renal disease, but it is crucial to use them responsibly and under medical guidance, especially for individuals with pre-existing kidney disease or those taking potentially nephrotoxic medications.