Short answer
In healthy people, studies have not found kidney harm at the doses trials use, including up to 30 g a day for five years in the ISSN’s review. Creatine does raise creatinine, the blood marker used to estimate kidney function, so a routine test can look worse than it is. Evidence in people with existing kidney disease is lacking, so they should ask their doctor first.
The creatinine confusion
Creatine breaks down into creatinine, and creatinine in the blood is what a standard kidney test measures. So someone taking creatine can show a higher creatinine, and a lower estimated filtration rate, without any change in the kidney itself. If you take creatine, tell whoever orders your bloodwork, so the number is read in context.
What the studies show
The 2017 ISSN position stand concluded that creatine at doses up to 30 g a day for up to five years was safe and well tolerated in healthy people, with no evidence of kidney damage. A 2019 meta-analysis in the Journal of Renal Nutrition reached a similar conclusion, and a 2025 review in Frontiers in Nutrition found no support for kidney harm in healthy adults at studied doses.
Who should be careful
The same 2025 review flags the gap: there is little research in people with existing kidney disease, and in pregnancy. Anyone with kidney disease, anyone on medicines that affect the kidneys, and anyone whose clinician tracks creatinine closely should talk to their doctor before starting. Dehydration from vomiting or diarrhea is a separate issue and applies to anyone.
Related questions
Does creatine dehydrate you or cause cramps?
Controlled studies haven’t supported either claim. Water retention in the first days is common; lasting dehydration is not what the research shows.
Should I stop creatine before a blood test?
Ask the clinician ordering it. Some prefer a pause so creatinine reflects the kidney alone; others just note that you take it.
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Sources
Published 2026-09-30 · Last checked 2026-09-30
Educational content, not medical advice. Made for the United States.