Concern about creatine and kidney function often begins with one laboratory marker: serum creatinine. Because creatinine is commonly used to estimate kidney filtration, a higher result can look alarming. Creatine supplementation, however, may also affect creatinine through its normal conversion into creatinine. This makes the result more complicated than a simple “higher means damage” rule.
A 2026 systematic review and meta-analysis in the Journal of Renal Nutrition examined this question using randomised evidence. Its findings did not show significant deterioration in the kidney-function outcomes evaluated, although they do not establish unlimited safety for every person, dose or duration.[1]
What Did the Researchers Analyse?
The review included 19 randomised controlled trials and one double-blind randomised crossover study. The three primary outcomes were serum creatinine, urea and estimated glomerular filtration rate, or eGFR.[1]
These markers do not answer exactly the same question.
Serum creatinine is a metabolic waste product used in common eGFR equations. Its concentration can be influenced by kidney filtration, muscle mass, meat intake, exercise and creatine supplementation. Urea is also affected by kidney clearance, but protein intake, hydration and other factors can change it.
eGFR is an estimate of filtration, usually calculated from serum creatinine rather than measured directly. Therefore, even eGFR results may require careful interpretation when creatinine production changes.
Looking at the markers together is more informative than treating serum creatinine alone as proof of kidney injury.
Creatinine Increased Slightly
Across 19 comparisons, creatine supplementation increased serum creatinine by an average of 0.13 mg/dL compared with control. The 95% confidence interval ranged from 0.07 to 0.18 mg/dL.[1]
This was a statistically significant increase, so it should not be described as “no effect on kidney tests.” However, serum creatinine is an indirect marker. A rise can influence creatinine-based kidney estimates without necessarily demonstrating structural kidney damage.
That is why the other pooled outcomes matter.
Urea and eGFR Did Not Change Significantly
Across 12 comparisons, the pooled mean difference in urea was −0.60 mg/dL, with a 95% confidence interval from −2.15 to 0.96 mg/dL. The interval crossed zero, meaning the meta-analysis did not find a significant difference between creatine and control.[1]
For eGFR, eight comparisons produced a pooled mean difference of −5.20 mL/min/1.73 m². The confidence interval was wide, ranging from −15.00 to 4.60, and also crossed zero.[1]
Taken together, the modest creatinine increase was not accompanied by statistically significant changes in urea or eGFR. This pattern does not support interpreting the creatinine increase alone as evidence that creatine damaged kidney filtration in the populations and study periods evaluated.
The authors also compared interventions lasting less than one month with those lasting longer than one month. Duration did not significantly modify the pooled results. However, this should not be presented as proof of long-term safety: the authors specifically called for additional randomised trials lasting more than one year.
What the Meta-Analysis Cannot Prove
The review does not establish that every creatine dose or supplementation pattern is safe for every person. Trial populations, protocols and laboratory methods varied, and only eight comparisons contributed to the eGFR analysis.
The results also should not be converted into medical advice for people with diagnosed kidney disease, abnormal kidney results or medicines that may affect renal function. These situations require individual clinical assessment.
Anyone having blood tests should tell the healthcare professional that they use creatine. Depending on the clinical situation, the professional may consider the wider laboratory pattern or alternative assessments rather than interpreting one creatinine result in isolation.
What This Means for Creatine Brands
The claim that “creatine raises creatinine, therefore it damages the kidneys” is not supported by this meta-analysis. The opposite statement—“creatine is kidney-safe for everyone”—also exceeds the evidence.
A responsible product FAQ should:
- explain the difference between creatine and creatinine;
- avoid presenting one blood marker as a diagnosis;
- identify the ingredient form and recommended intake;
- distinguish evidence from healthy study populations from advice for people with kidney disease; and
- avoid turning an ingredient-level meta-analysis into proof for a specific finished product.
SRS Nutrition Express supplies creatine monohydrate with defined specifications, batch documentation and particle-size options for different applications. These controls support raw-material quality and formulation work. They do not replace clinical advice or prove a health outcome for every consumer.
For creatine monohydrate specifications, samples or application discussions, contact SRS Nutrition Express before finalising your product brief.
References
- Tsiaras A, Loufopoulos G, Theodoridis X, Liakopoulos V, Poulia KA, Chourdakis M. The effect of creatine supplementation on kidney function: a systematic review and meta-analysis of randomized controlled trials. Journal of Renal Nutrition. Published online April 24, 2026. doi: 10.1053/j.jrn.2026.04.010.
- Naeini EK, Eskandari M, Mortazavi M, Gholaminejad A, Karevan N. Effect of creatine supplementation on kidney function: a systematic review and meta-analysis. BMC Nephrology. 2025;26:622. doi: 10.1186/s12882-025-04558-6.
- de Souza e Silva A, Pertille A, Reis Barbosa CG, et al. Effects of creatine supplementation on renal function: a systematic review and meta-analysis. Journal of Renal Nutrition. 2019;29(6):480–489. PubMed record.
Post time: Aug-14-2026
