Creatine, Kidney Questions and Creatinine Testing
Why creatine can raise a blood creatinine number without changing measured kidney filtering, what trials found, and who should ask a clinician before using it.
Content last updated . This page has not been medically reviewed.
Urgent first: who should ask a clinician
People with kidney disease, a kidney transplant, dialysis or abnormal kidney tests should ask their kidney doctor or pharmacist before using creatine. The National Kidney Foundation (US) lists creatine among supplements with a high level of risk for people with kidney disease, especially kidney failure. [1] A 2026 review said concerns persist about the renal safety of creatine, especially in people with impaired kidney function. [2] Authors of one safety review advised against higher creatine amounts for people with kidney disease or a risk of it, such as diabetes, high blood pressure or reduced kidney filtering. [3]Early kidney disease usually has no symptoms, so a person may not know they have it. [4] Do not stop a prescribed medicine because of anything on this page.
The short answer
There are two separate questions: does creatine harm healthy kidneys, and why can a kidney blood test look worse? In pooled trials, people taking creatine had a blood creatinine about 0.13 to 0.14 mg/dL higher on average. [5] [6] When kidney filtering was measured directly with a marker (Cr-EDTA), the larger analysis found no significant difference, and its authors said the rise likely reflects altered creatinine metabolism rather than kidney injury. [6] Trials longer than a year are still missing, and evidence in people who already have kidney disease is thinner. [5]How creatine, creatinine and the test connect
Muscle breaks creatine down to creatinine, a waste product the kidneys filter out of the blood. [7] [8] Doctors use blood creatinine to estimate kidney filtering. [4] But creatinine also depends on muscle mass and food, and both blood and urine creatinine can rise with creatine supplements or meat. [7]MedlinePlus says a high creatinine does not always mean a kidney problem; dehydration, intense exercise or a diet high in meat can also raise it. [8] The deeper explanation, including cystatin C, is on Creatinine, eGFR and Cystatin C.
What studies found
The 1998 case report
Part of the worry began with a 1998 case report of a young man with long-standing kidney disease. [7] A 2021 position paper says later case reports were confounded by medicines, pre-existing kidney disease, other supplements, very high amounts and steroid use. [7] That paper's authors include people with ties to a creatine maker. [7]What to tell the clinician
- MedlinePlus advises telling your provider everything you take before a creatinine test, and not stopping any medicine unless the provider says so. [8]
- A single high creatinine cannot diagnose a condition; retesting and other tests are usual. [8]
- Proper evidence not found: a standard for how long creatine should be paused before a kidney test. We searched PubMed for creatine with creatinine and cystatin C, and read MedlinePlus, NIDDK and National Kidney Foundation pages. The clinician decides.
Frequently asked questions
Does creatine damage the kidneys?
In healthy people, a 2021 position paper found no adverse kidney effects at recommended amounts, and meta-analyses found creatinine rises without clear changes in other kidney markers. [7] [6] Longer trials are still wanted. [5]
Why is my creatinine high while I use creatine?
Creatine supplements and meat can raise blood creatinine without kidney damage, so the number needs context. [7] Your clinician may repeat it or order other tests. [8]
Should I stop creatine before a blood test?
We found no standard in the sources we read. Tell the person ordering the test and let them decide. [8]
Can people with kidney disease use creatine?
Ask your kidney doctor first. The National Kidney Foundation lists creatine among high-risk supplements for kidney disease. [1]
Is there a test not based on creatinine?
Cystatin C is a protein some clinicians use instead of or with creatinine in certain people. [12] It can be inaccurate in some conditions, such as untreated thyroid problems or steroid use. [13]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read the evidence labels
Labels used on this page: "evidence in adequately nourished people", "mixed", "promising but limited" and "insufficient evidence". Most trials were short, and a measured change in a blood marker is not the same as a health outcome.
| Question | What the source found | Evidence label |
|---|---|---|
| Does creatine raise serum creatinine? | A meta-analysis of 19 trials plus one crossover study found a rise of 0.13 mg/dL. [5] A larger one (26 studies, 1,036 people) found 0.14 mg/dL, with very different results between studies (I2 = 93.9%). [6] | Evidence in adequately nourished people |
| Does it change estimated filtering (eGFR)? | One analysis found no significant difference, though the range was wide (-15.00 to 4.60 mL/min/1.73 m2). [5] The other found lower creatinine-based GFR but no significant change by Cr-EDTA. [6] | Mixed, with a testing explanation |
| Urea, urine albumin and protein | No significant differences in the larger analysis. [6] | Promising but limited |
| Cystatin C | In a trial of 18 healthy men, cystatin C fell over time with exercise training. [9] In a 2-year trial of people with Parkinson disease, cystatin C stayed normal. [10] | Promising but limited |
| Type 2 diabetes | A 12-week trial found no significant difference in measured clearance. [11] | Promising but limited |
| Longer than one year | The authors say longer randomized trials are needed. [5] | Insufficient evidence |
| People with kidney disease | The larger analysis included them, and in the hemodialysis subgroup serum creatinine rose. [6] A 2026 review says concerns remain. [2] | Insufficient evidence |
The Cr-EDTA test is a measured GFR: a marker is injected and the kidneys' clearance of it is tracked. MedlinePlus calls this test complicated and not widely available. [12]
Other safety points
References
- National Kidney Foundation (US). Herbal Supplements and Kidney Disease. Read 2026-10-23.
- Pereira JP, Leal VO, Trigueira P, et al. Creatine supplementation in patients with kidney disease - harm or benefit? Nephrol Dial Transplant 2026 (narrative review, abstract read). Read 2026-10-23.
- Kim HJ, Kim CK, Carpentier A, Poortmans JR. Studies on the safety of creatine supplementation. Amino Acids 2011 (narrative review, abstract read). Read 2026-10-23.
- National Institute of Diabetes and Digestive and Kidney Diseases (US). Chronic Kidney Disease Tests & Diagnosis. Read 2026-10-23.
- Tsiaras A, Loufopoulos G, Theodoridis X, et al. The Effect of Creatine Supplementation on Kidney Function: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Ren Nutr 2026 (abstract read). Read 2026-10-23.
- de Souza Almeida A, da Silva LOD, Takahasi BNA, et al. Impact of creatine supplementation on kidney health: a systematic review and meta-analysis. Int Urol Nephrol 2026 (abstract read; authors declare no competing interests). Read 2026-10-23.
- Antonio J, Candow DG, Forbes SC, et al. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr 2021 (narrative review, full text read via PMC7871530; several authors declare creatine-industry advisory roles). Read 2026-10-23.
- MedlinePlus (US National Library of Medicine). Creatinine Test. Read 2026-10-23.
- Gualano B, Ugrinowitsch C, Novaes RB, et al. Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial. Eur J Appl Physiol 2008 (abstract read). Read 2026-10-23.
- Bender A, Samtleben W, Elstner M, Klopstock T. Long-term creatine supplementation is safe in aged patients with Parkinson disease. Nutr Res 2008 (abstract read). Read 2026-10-23.
- Gualano B, de Salles Painelli V, Roschel H, et al. Creatine supplementation does not impair kidney function in type 2 diabetic patients: a randomized, double-blind, placebo-controlled, clinical trial. Eur J Appl Physiol 2011 (abstract read). Read 2026-10-23.
- MedlinePlus (US National Library of Medicine). Estimated Glomerular Filtration Rate (eGFR) and GFR Tests. Read 2026-10-23.
- National Kidney Foundation (US). Cystatin C. Read 2026-10-23.