🟢 Strong Evidence
A systematic review and meta-analysis of 21 studies published in 2025 confirms what many athletes already suspect: creatine supplementation does not damage kidney function, despite raising serum creatinine levels on standard blood tests. The confusion stems from a fundamental misinterpretation of how the kidney function equation works when creatine stores increase.
Key takeaways
- Creatine supplementation increases serum creatinine but does not impair actual kidney function, according to a 2025 systematic review of 21 studies
- The 2025 analysis by Kreider et al. in the Journal of the International Society of Sports Nutrition reviewed 685 human clinical trials involving over 26,000 participants with no evidence of kidney damage
- Doctors interpreting blood tests should distinguish between elevated creatinine (a mathematical artifact of increased muscle creatine stores) and actual kidney dysfunction (measured by cystatin C, proteinuria, and albuminuria)
Study at a Glance
| Source | Journal of the International Society of Sports Nutrition |
| Study type | Systematic review and meta-analysis |
| Sample size | 685 human clinical trials, 26,000+ participants |
| Population | Individuals taking creatine supplementation |
| Country | International (multi-centre analysis) |
Creatine and Kidney Function: What Changes and What Doesn’t
Results from 21-study meta-analysis showing creatinine elevation versus stable kidney health markers, 2025
Source: 2025 Systematic Review and Meta-Analysis (21 studies) | Georgian Medical Journal News
How the Misconception Began
The myth that creatine damages kidneys originated from a correct observation interpreted incorrectly. Creatine is stored in skeletal muscle primarily as phosphocreatine, and it degrades spontaneously and irreversibly into creatinine at a rate of approximately 2% per day. When individuals supplement with creatine, they increase total body creatine stores, which produces more creatinine as a waste product.
On a standard metabolic panel, doctors measure serum creatinine and use it to calculate estimated glomerular filtration rate (eGFR)—the primary marker of kidney function. The equation assumes that creatinine production is relatively constant. When creatinine levels rise due to increased creatine supplementation, the mathematical formula interprets this as reduced kidney filtration capacity. However, the kidney is filtering and excreting at its normal rate; there is simply more substrate being produced.
What the 2025 Evidence Shows
The 2025 systematic review published in the Journal of the International Society of Sports Nutrition examined 21 studies investigating creatine supplementation and kidney function. Results confirmed the expected finding: creatine was associated with a small but statistically significant increase in serum creatinine (mean difference: 0.07 micromol/L). Critically, however, there were no changes in measured glomerular filtration rate, cystatin C, proteinuria, or albuminuria—the markers that actually reflect kidney health independent of creatinine metabolism.
The largest safety analysis, conducted by Kreider and colleagues in the same 2025 review for the Journal of the International Society of Sports Nutrition, examined 685 human clinical trials involving over 26,000 participants. This comprehensive analysis found no evidence of kidney damage attributable to creatine supplementation across the entire population studied. For clinicians reviewing laboratory results, this distinction is essential: creatinine elevation alone does not indicate kidney dysfunction when other renal markers remain stable.
Creatine supplementation increased serum creatinine but produced no changes in measured GFR, cystatin C, proteinuria, or albuminuria across 21 studies—confirming that elevated creatinine is a mathematical artifact, not evidence of kidney damage.
— 2025 Systematic Review and Meta-Analysis, Journal of the International Society of Sports Nutrition
Clinical Interpretation and Patient Safety
This evidence carries important implications for both patients using creatine supplements and clinicians interpreting their laboratory results. Patients who have been advised to discontinue creatine based solely on elevated serum creatinine should understand that this elevation reflects increased muscle creatine stores, not kidney dysfunction. Clinicians should avoid reflexively recommending cessation of creatine supplementation when serum creatinine rises, provided that other renal function markers (cystatin C, proteinuria, albuminuria) and measured GFR remain normal.
The evidence is particularly reassuring for individuals with pre-existing kidney disease, though those populations warrant closer monitoring. The clinical evidence base now provides clear guidance that creatine supplementation, at standard doses, does not appear to pose kidney damage risk in healthy individuals. This represents a significant shift from the precautionary stance that once dominated practice guidelines.
What this means
Frequently asked questions
Does creatine supplementation actually damage the kidneys?
No. A 2025 systematic review of 21 studies and meta-analysis found no evidence that creatine supplementation damages kidney function. Although serum creatinine increases, this reflects more creatinine production from higher muscle creatine stores—not reduced kidney filtration. Markers of actual kidney health (measured GFR, cystatin C, proteinuria, albuminuria) remain unchanged.
Why do doctors see elevated creatinine on blood tests if creatine is safe?
Creatinine is a breakdown product of creatine stored in muscle. When you supplement with creatine, you store more creatine in your muscles, which produces more creatinine waste. The standard kidney function equation assumes creatinine production is constant, so it misinterprets the increase as reduced kidney function. It is not—it is simply more waste being produced at the same filtration rate.
Should people with kidney disease avoid creatine supplementation?
Individuals with pre-existing kidney disease should consult their nephrologist before using creatine, as their kidneys may have reduced filtration capacity and could be affected differently. However, the 2025 evidence shows that in healthy individuals, creatine supplementation does not cause kidney damage. Those with kidney disease represent a different population requiring individualized assessment.
The persistent myth about creatine and kidney damage highlights a broader challenge in translating biochemical data into clinical practice: accurate interpretation of laboratory values requires understanding not just the number, but the mechanism behind it. As new research continues to emerge, clinicians and patients benefit from evidence-based reassurance that standard creatine supplementation, supported by over 26,000 participants across hundreds of clinical trials, does not pose a kidney safety risk in healthy individuals.
Source: Kreider et al., Journal of the International Society of Sports Nutrition, 2025
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