TL;DR (≤60 words)
In healthy adults, research shows that creatine does not harm kidney function. Serum creatinine may rise slightly due to creatine metabolism—which is not evidence of kidney damage. In doubt? Ask your doctor for cystatin-C or eGFRcr-cys (KDIGO 2024). Stick to 3–5 g/day and stay well hydrated. PMC+1
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Intro (Why it matters)
“Creatine is bad for your kidneys.” You hear it often, and it's persistent. The confusion mainly arises because serum creatinine sometimes increases slightly with creatine use. This seems concerning but is explained by increased creatinine formation from creatine, without demonstrable kidney damage in studies on healthy individuals. In this guide, you'll get the facts, lab test tips, and practical do's & don'ts. PMC
What is the difference between creatinine and cystatin-C?
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Creatinine is a breakdown product of creatine/phosphocreatine. If you supplement creatine, serum creatinine can rise slightly—even if your kidneys are functioning perfectly.
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Cystatin-C is independent of muscle mass/creatine intake and often provides a more reliable picture when creatinine is misleading. KDIGO 2024 therefore recommends using cystatin-C or the eGFRcr-cys combination where possible. kdigo.org
What does science say? (key findings)
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RCT with "new" kidney damage biomarkers (KIM-1, MCP-1): 3–5 g/day, 35 days, no deterioration; small increase in creatinine remained within reference range. Conclusion: safe for healthy men. PMC
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Meta-analysis (2019, 15 RCTs/cohorts): no harmful effect on serum creatinine and urea within usual dosages/duration. PubMed
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ISSN position stand (2017): creatine monohydrate is safe and effective in healthy individuals; concerns mainly arise from case reports or misinterpretation. BioMed Central
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EFSA (EU claim): performance claim with ≥3 g/day; no indications that this dosage is harmful to healthy adults. European Food Safety Authority
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Mechanistic/overview (2023): rising serum creatinine ≠ kidney damage; evaluate with better markers (cystatin-C, modern panels). PMC
Important: individuals with pre-existing kidney conditions fall outside the healthy population in the studies above. Always consult your doctor in such cases. PMC
Practical: how to use creatine "kidney-smart"
Dosage
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Maintenance: 3–5 g/day creatine monohydrate (gummies or powder).
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Loading phase (optional): 20 g/day (4×5 g) for 5–7 days; speeds up saturation, not necessary. BioMed Central
Gummies
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Check mg per gummy. For 1,000 mg per gummy: 3–5 gummies/day. Consistency is more important than timing. (See our lab test on our product page)
Lab test tips (if in doubt or for medical follow-up)
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Ask your doctor for cystatin-C or eGFRcr-cys, especially if serum creatinine rises slightly after starting creatine.
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Evaluate over at least 3 months (CKD definition) and in context (training, protein intake, hydration). kdigo.org
Hydration
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Drink according to thirst and exertion; be mindful of heat/sweat loss. (General sports nutrition practice.)
Target groups & nuance
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Healthy adults: evidence indicates safe use within guidelines. PubMed
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Type 2 diabetes / vascular conditions: small RCTs showed no adverse kidney effects, but medical consultation is still advisable. PMC
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Existing kidney disease, transplantation, heavy medication (NSAIDs, loop diuretics, ACE inhibitors, etc.): always involve a doctor. Focus on monitoring with suitable markers (cystatin-C). kdigo.org
Do’s & Don’ts (checklist)
Do
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Use 3–5 g/day monohydrate; choose a fixed time.
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Check label (mg/gummy) and choose brands with CoA/lab tests.
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Discuss cystatin-C/eGFRcr-cys with your doctor if creatinine rises. kdigo.org
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Maintain hydration and overall lifestyle.
Don’t
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Don't be alarmed by a slight increase in serum creatinine; this can be physiological. Assess with better markers. PMC
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Don't overdose or yo-yo with intake.
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Do not draw conclusions from one lab value without context/time.
Conclusion
Creatine does not harm your kidneys if you are healthy and dose correctly. Interpret blood values smartly: serum creatinine may rise without harm; if necessary, use cystatin-C/eGFRcr-cys. Choose the form you can maintain daily.
• Order Beargymmies® Performance+ (sugar-free, with taurine/magnesium/potassium) → https://www.zooonutrition.com/products/suikervrij-beargymmies-performance-plus-creatine-gummies-vegan
• Or choose Original Beargymmies® → https://www.zooonutrition.com/products/creatine-monohydraat-gummie-beertjes-beargymmies
Sources (clickable; old → new)
• Poortmans JR & Francaux M. (1999). Long-term oral creatine supplementation does not impair renal function in healthy athletes. Med Sci Sports Exerc. https://pubmed.ncbi.nlm.nih.gov/10448902/
• Kreider RB, et al. (2017). ISSN position stand: Safety & efficacy of creatine. J Int Soc Sports Nutr. https://doi.org/10.1186/s12970-017-0173-z BioMed Central
• Souza ESA, et al. (2019). Effects of creatine supplementation on renal function: systematic review/meta-analysis. J Ren Nutr. https://pubmed.ncbi.nlm.nih.gov/31375416/ PubMed
• Neto JOV, et al. (2020). Novel renal biomarkers show creatine supplementation is safe (RCT). NDT. https://pmc.ncbi.nlm.nih.gov/articles/PMC7329184/ PMC
• Antonio J, et al. (2021). Common questions & misconceptions about creatine. J Int Soc Sports Nutr. https://jissn.biomedcentral.com/articles/10.1186/s12970-021-00412-w BioMed Central
• EFSA NDA Panel (2011). Creatine—EU performance claim (≥3 g/day). EFSA Journal. https://www.efsa.europa.eu/en/efsajournal/pub/2303 European Food Safety Authority
• KDIGO (2024). CKD Guideline—cystatin-C and eGFRcr-cys recommendations. https://kdigo.org/wp-content/uploads/2024/03/KDIGO-2024-CKD-Guideline.pdf kdigo.org
