Creatine and creatinine are related, but they are not the same. Creatine helps supply energy to muscles; creatinine is a product of creatine metabolism that is measured to help assess kidney function.
Taking creatine can raise blood creatinine and affect an estimated kidney filtration rate calculated from it. That change does not, by itself, prove kidney damage. It also should not be dismissed without considering the rest of your clinical information.
Previous test results, muscle mass, medicines, supplements and, when appropriate, other blood and urine tests all help a healthcare professional interpret the result.
Creatine vs creatinine: what is the difference?
Creatine
A compound made by the body and also obtained from food and supplements. In muscle, creatine and phosphocreatine help regenerate ATP during intense exercise.
Creatinine
A waste product formed naturally from creatine and phosphocreatine. The kidneys remove it from the blood, so its concentration is used as one marker in kidney assessment.
Blood creatinine is not a direct measurement of how much creatine supplement you take. For an overview of the supplement, see our guide to creatine monohydrate and its uses.
Can creatine supplements raise creatinine levels?
Yes. Creatine supplementation is one factor that can raise blood creatinine without necessarily causing an equivalent reduction in kidney filtration.
The National Kidney Foundation also identifies high muscle mass, recent intense exercise, cooked meat and certain medicines as factors that can influence creatinine results.
That is why your clinician needs to know if you take creatine. It does not mean every elevated result is caused by the supplement: other causes, including a genuine kidney problem, can also be present.
What does the research say about creatine and kidney function?
Creatinine can change without every marker changing in the same way
A meta-analysis published in April 2026 found an average increase in blood creatinine of approximately 0.13 mg/dL with supplementation. It found no statistically significant differences between groups in blood urea or estimated glomerular filtration rate.
That figure is an average across studies, not a permitted or safe increase for an individual. The authors called for more trials lasting longer than one year.
The way kidney filtration is assessed matters
A separate 2026 meta-analysis included 26 studies and 1,036 participants. It found increased creatinine and lower filtration estimates using creatinine-based methods, but no statistically significant difference in filtration measured using the tracer Cr-EDTA.
The authors suggested that the changes may reflect altered creatinine metabolism rather than kidney injury. The difference between the reviews shows why it is important to check the marker and measurement method. A non-significant difference does not prove that a change is impossible.
These findings do not guarantee safety in every situation. If you have kidney disease or an abnormal test result, discuss creatine use with the healthcare team caring for you.
Estimated vs measured GFR: what do the results mean?
Creatinine-based eGFR
Estimated glomerular filtration rate, or eGFR, is calculated using an equation. When that equation uses creatinine, a change in creatinine can change the estimate without an equivalent change in actual filtration.
Measured GFR
Measured GFR uses the clearance of an administered marker, such as iohexol or certain tracers. It is a specialised test used when greater accuracy may affect a clinical decision.
A higher creatinine result and a lower creatinine-based eGFR are not two independent findings: the latter may have been calculated from the former. Both still need clinical interpretation.
How cystatin C and urine tests add context
Cystatin C: another marker used to estimate filtration
Cystatin C may help when creatinine gives a less reliable estimate, including in some people with high muscle mass. Some equations use both markers together.
It is not a perfect test and does not automatically replace creatinine. Thyroid disorders and corticosteroid use, among other factors, can affect its interpretation. A clinician decides which estimate is most useful in a particular situation.
Urine albumin: different information from blood creatinine
Albumin is a protein that can appear in urine in abnormal amounts when the kidneys are damaged. A urine albumin-to-creatinine ratio helps assess this loss.
The urine creatinine used in that ratio is a different measurement from blood creatinine. Intense exercise can also temporarily raise urine albumin, so an abnormal result may need confirmation as directed by a clinician.
What to tell your healthcare professional before a blood test
Product and amount
Share the product name, creatine form, amount taken each day and any other supplements.
How long you have used it
Explain when you started, whether you used a loading phase and when you last took it.
Recent training and circumstances
Mention recent intense exercise, dietary changes, illness or fluid loss.
Medical history and medicines
Bring previous results and share known conditions and all medicines you take.
A photo of the label can help. For example, Centenarian Road’s Creapure® creatine monohydrate lists creatine monohydrate as its only ingredient and a recommended daily serving of 3 g. Tell your clinician the amount you actually take, even if it differs from the label.
Should you stop taking creatine before a blood test?
There is no universal number of days that applies to everyone. The decision depends on what the test is intended to assess and your clinical circumstances.
Before the test, ask the professional who ordered it whether you should change your supplement use, exercise or diet. If they recommend a pause, confirm its duration and when any repeat test should take place.
Follow the laboratory’s preparation instructions and do not stop prescribed medicines on your own. The aim is a result that can be interpreted accurately, not simply a lower number.
What to do if your creatinine result is high
Ask a healthcare professional to review the result and tell them about your creatine use. They can compare it with previous results, consider the eGFR and check for other abnormalities.
Depending on the circumstances, they may repeat tests, assess urine, use cystatin C or consider other investigations. Not everyone needs every test.
Seek urgent medical attention if you also have a marked reduction in urination, shortness of breath, significant swelling or confusion. Some kidney injuries cause no symptoms, so feeling well does not make an abnormal result safe to ignore.
Frequently asked questions about creatine and creatinine
Can a hard workout affect a creatinine blood test?
Recent intense exercise can influence creatinine levels. Tell the clinician when and how hard you trained, and follow the preparation instructions they give you.
Is there a separate normal creatinine range for people taking creatine?
Do not apply a different threshold solely because you use a supplement. Your clinician considers the laboratory range, your previous results and the wider clinical picture.
Can cooked meat affect my test result?
Cooked meat can temporarily raise blood creatinine. Ask the healthcare professional or laboratory whether you need to avoid it before your particular test.
Can I take creatine if I already have kidney disease?
Discuss it with the team treating you. Results from studies in other participants do not replace an individual assessment of your kidney function, medicines and needs.
Scientific references and sources
Sources reviewed: 29 October 2026. Test results should be interpreted by a healthcare professional who knows your circumstances.
- Tsiaras A et al. The Effect of Creatine Supplementation on Kidney Function: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. 2026.
- de Souza Almeida A et al. Impact of creatine supplementation on kidney health: a systematic review and meta-analysis. 2026.
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. GFR estimation and measurement.
- National Kidney Foundation: Creatinine. Factors that can affect results.
- National Kidney Foundation: Cystatin C. Uses and limitations.
- MedlinePlus: Creatinine Test. Test preparation and interpretation.
- MedlinePlus: Albumin-to-Creatinine Ratio. Urine testing and possible temporary influences.
- NHS: Acute kidney injury. Symptoms and when to seek help.
