Effect of creatine supplementation on kidney function: a systematic review and meta-analysis.

backgroundCreatine monohydrate is a widely used dietary supplement with proven benefits in athletic performance and potential therapeutic applications in clinical populations. However, concerns regarding its impact on renal function persist, largely due to elevated serum creatinine levels associated with creatine intake.

methodsA comprehensive literature search was conducted in PubMed, Scopus, Web of Science, and Google Scholar for studies published between January 2000 and March 2025. Primary outcomes were serum creatinine and glomerular filtration rate (GFR). Meta-analyses were performed using a random-effects model, with subgroup analysis by supplementation duration.

resultsTwenty-one studies were included in the systematic review, and 12 studies (177 participants in the creatine group and 263 in control) were eligible for meta-analysis of serum creatinine levels. Creatine supplementation was associated with a small but statistically significant increase in serum creatinine (MD: 0.07 µmol/L; 95% CI: 0.01 to 0.12; p = 0.03). Subgroup analysis of the creatinine outcome based on follow-up duration revealed that the intervention effect was significant in studies with a follow-up of ≤ 1 week (MD = 0.12; 95% CI: 0.03 to 0.21). However, no significant effect was observed in studies with a follow-up of 1 to 12 weeks (MD = 0.04; 95% CI: - 0.09 to 0.17). The effect became significant again in studies with a follow-up of more than 12 weeks. The meta-analysis revealed a non-statistically significant differences in GFR following creatine supplementation compared to control.

conclusionCreatine supplementation is associated with a modest, transient increase in serum creatinine levels, likely due to metabolic turnover rather than renal impairment. No significant changes were observed in GFR, suggesting preserved kidney function. CLINICAL TRIAL NUMBER: Not applicable.