I take creatine and my creatinine is high. Is it kidney damage?

Written by The Wellness Team

Reviewed by The Wellness Clinical Team. Last reviewed 22 October 2026.

Quick answer, as of October 2026: Usually not. Creatine often raises blood creatinine without harming the kidneys, because the body breaks creatine down into creatinine. That can make the standard kidney test, eGFR, look lower than your kidneys really are. A cystatin C test, which comes from cells other than muscle, gives a clearer answer. The Online GP by The Wellness offers doctor-led blood panels from £350.

Does creatine raise creatinine, and does that mean kidney damage?

Not necessarily. Creatinine is the natural breakdown product of creatine, which is stored in muscle. A 2023 narrative review in Nutrients explains that creatine is spontaneously and irreversibly converted to creatinine, so taking creatine can raise serum creatinine. Laboratories use blood creatinine to estimate kidney filtration, the eGFR, so a higher creatinine produces a lower eGFR even when the kidneys are filtering normally.

The same review concluded that any blood marker influenced by creatine metabolism may not be accurate enough to judge kidney function in people taking creatine, and advised assessing several markers of kidney function instead.

Key points

  • Creatine converts to creatinine, so taking creatine can raise blood creatinine and lower the eGFR estimated from it, without a change in kidney function.
  • A 2023 review in Nutrients advised using multiple markers of kidney function in people who take creatine.
  • A September 2026 NutraIngredients report described a population study of almost 5,000 people in which higher dietary creatine was not linked to raised cystatin C, a kidney marker that does not come from muscle.
  • KDIGO's 2024 guideline recommends estimating GFR from creatinine and cystatin C together when cystatin C is available.
  • NICE advises adults not to eat meat in the 12 hours before a blood test for eGFR.

Send your kidney results to a doctor on WhatsApp

What does the evidence say about creatine and the kidneys?

A NutraIngredients report from 1 September 2026 summarised the current debate. It noted that early case reports linking creatine to kidney problems involved people with pre-existing kidney disease and relied on serum creatinine, a marker that is unreliable in the context of creatine supplementation. It cited the population study of almost 5,000 people in which higher dietary creatine intake was not associated with raised cystatin C.

The researchers quoted in that report said the evidence supports kidney safety in healthy people, while evidence in people with kidney disease is limited. One advised that anyone with kidney disease or another health condition should get medical clearance before supplementing with creatine.

What else can raise creatinine?

Creatine is one of several reasons a fit person can have a raised creatinine with healthy kidneys. Doctors consider each of these before drawing any conclusion.

  1. Higher muscle mass, because creatinine comes from muscle.
  2. Creatine supplements.
  3. Eating meat shortly before the test. NICE advises adults not to eat any meat in the 12 hours before a blood test for eGFR.
  4. Real kidney problems, which is why a doctor interprets the result rather than assuming a cause.

Our guide to finger-prick and venous blood tests explains why kidney function is better checked from a venous sample when a decision depends on it.

How do doctors check kidney function properly if I take creatine?

Doctors check kidney function properly by adding tests that creatine does not affect, and by looking at the full picture rather than a single creatinine. The KDIGO 2024 guideline recommends that if cystatin C is available, GFR should be estimated from the combination of creatinine and cystatin C.

  1. Cystatin C, used with creatinine to calculate a combined eGFR.
  2. Urine albumin, which looks for protein leaking through the kidneys. KDIGO advises testing people at risk using both urine albumin and GFR.
  3. A repeat creatinine, with any pause in creatine agreed with your doctor.
  4. Comparison with any previous results, as a stable trend is reassuring and a falling eGFR over time is not.

When should a high creatinine be taken seriously?

A high creatinine should be taken seriously if eGFR stays low on repeat testing with cystatin C, if it is falling over time, or if there is protein or blood in the urine. High blood pressure, diabetes, a family history of kidney disease, swollen ankles or foamy urine also need a doctor's assessment, whether or not you take creatine.

People with known kidney disease should get medical advice before taking creatine.

Book a video consultation about your kidney results on WhatsApp

What should I do before an executive medical or insurance medical?

Tell the doctor you take creatine before your blood test, so your kidney results are read in context. An unexplained low eGFR can lead to further questions and repeat testing.

  1. Mention creatine, protein powders and any other supplements on your intake form.
  2. Avoid meat for 12 hours before the test, as NICE advises.
  3. Ask for cystatin C to be added, so a combined eGFR is reported.

Book a call about a kidney-focused blood panel on WhatsApp

Is creatine safe to keep taking?

For healthy adults, the NutraIngredients report quoted researchers describing a large body of data in healthy people of all ages showing creatine is safe. Your doctor can confirm it suits you once your kidney results are clear.

Our guide to what a full private blood test should include explains how kidney markers fit into a wider health check.

How much does a kidney function blood test cost?

As of October 2026, The Online GP by The Wellness offers three doctor-led blood panels. Longevity+ starts from £1,395 and is the most comprehensive, followed by Advanced Health from £650 and Core Wellness from £350. A doctor confirms whether to add cystatin C and any other markers before you book, and a GMC-registered doctor explains every result.

A video consultation to review results from an executive medical or elsewhere starts from £150 for up to 30 minutes.

Can a doctor tell me if my creatinine result is a concern?

Yes. Send your creatinine and eGFR results, your creatine dose and your training routine on WhatsApp. A doctor tells you whether a repeat test with cystatin C, a wider panel or a consultation is the right next step.

Frequently asked questions

Should I stop creatine before a blood test?

Tell the doctor you take creatine. If your creatinine is raised, the doctor may suggest a short pause before a repeat test, or add cystatin C so you can carry on.

Does creatine affect eGFR?

Yes. eGFR is usually calculated from creatinine, so creatine can lower the reported eGFR without any change in how well your kidneys filter.

Is cystatin C affected by creatine?

Cystatin C does not come from muscle, and a population study of almost 5,000 people found no link between dietary creatine and raised cystatin C, as reported by NutraIngredients in 2026.

Can protein shakes raise creatinine?

Meat eaten shortly before a test can affect the result, which is why NICE advises avoiding it for 12 hours. Tell the doctor about protein supplements as well as creatine.

Is creatine bad for your kidneys?

In healthy adults, the 2026 NutraIngredients report found the evidence supports kidney safety. People with kidney disease should get medical advice before taking it.

What is a normal creatinine level?

Normal ranges vary by laboratory, age, sex and muscle mass. Doctors interpret creatinine alongside eGFR, cystatin C and urine tests rather than on its own.

Sources

This article is general information and not a substitute for medical advice about your own health.

The Wellness Team
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