Creatine and kidney function across 21 studies
What it found
In people, creatine supplements raised blood creatinine a little but made no real difference to how well the kidneys filtered blood.
The authors say this fits with a normal body change, not kidney damage.
What they found
Studies in people
Blood creatinine
Pooled results from 12 studies showed a small rise in blood creatinine with creatine supplements compared with control. The authors describe this rise as modest.
Timing of the rise
The rise in blood creatinine was seen in studies lasting 1 week or less and again in studies longer than 12 weeks. Studies lasting 1 to 12 weeks showed no clear difference.
Kidney filtration rate
Across 5 studies, creatine supplements made no significant difference to glomerular filtration rate, the measure of how well the kidneys filter blood, compared with control.
Other findings
Why creatinine rises
The authors say the creatinine rise is likely a normal result of creatine breaking down in the body, not a sign of kidney damage. Creatinine is a breakdown product of creatine.
Study quality
Most studies had some risk of bias, with missing details on how treatments were assigned and how dropouts were reported. Many were small and short.
How it was done
People worry that creatine might harm the kidneys, largely because taking it can raise blood creatinine, a marker used to estimate kidney function. The authors wanted to pull together the evidence and see whether kidney function actually changes.
They searched medical databases for human studies published between January 2000 and March 2025. They found 21 studies, and pooled results from 12 of them for blood creatinine (177 people taking creatine and 263 controls) and 5 for filtration rate (69 people taking creatine and 74 controls).
What it can’t tell you
- Most included studies were short to moderate in length, so long-term safety data beyond one year remain sparse.
- The studies used different lab methods to measure creatinine, and most did not report which method they used, which may affect the results.
- Dosage and training status were not consistently reported, so the authors could not fully explore how these factors affect kidney function.
Who paid
- Conflicts
- Declarations. Ethics approval and consent to participate: Not applicable because this is systematic review and meta-analysis. Consent for publication: Not applicable because this is systematic review and meta-analysis. Competing interests: The authors declare no competing interests.
- Authors work at
- Isfahan University of Medical Sciences, Iran
The paper
- Title
- Effect of creatine supplementation on kidney function: a systematic review and meta-analysis
- Type
- Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Naeini EK, Eskandari M, Mortazavi M, Gholaminejad A, Karevan N (2025). Effect of creatine supplementation on kidney function: a systematic review and meta-analysis. BMC nephrology. doi:10.1186/s12882-025-04558-6Free full textPubMed 41199218DOI
Summary written 29 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error