Is Creatine Safe? Kidneys, Heart Health and Long-Term Daily Use

TL;DR

For healthy adults, yes. Creatine monohydrate is one of the most studied supplements, and trials of up to around five years at 3 to 5g a day have not found harm to the kidneys, liver or blood pressure, or any need to cycle off. It does raise blood creatinine, which can make a routine kidney test look worse than it is. Anyone with a kidney, liver or heart condition, who is pregnant, or who takes regular medication should check with their GP first.

Most creatine safety worries start in one of two places: a forum thread about kidneys, or a GP querying a blood test result. Both lead back to the same root. Creatine breaks down into creatinine, the marker routine kidney tests rely on, so taking it can make healthy kidneys look slower on paper than they really are.

This guide works through what the research actually measured on kidneys, blood pressure and long-term daily use, and it is clear about who should check with a GP before starting.

Why creatine is one of the most studied supplements

Creatine monohydrate has been studied in humans for more than three decades, across hundreds of trials in athletes, older adults, women and clinical groups.That depth matters: a problem that could hide in a few small studies is far more likely to surface across hundreds.

The International Society of Sports Nutrition (ISSN) has reviewed this evidence twice. Its 2017 position stand (Kreider et al.) concluded that creatine monohydrate is safe and well tolerated in healthy people at recommended doses, and a 2021 follow-up (Antonio et al.) tested common misconceptions, including kidney harm and cycling off.[1] For UK and European readers, the European Food Safety Authority (EFSA) also assessed creatine monohydrate in 2004 and concluded that intakes of around 3g a day are unlikely to pose a risk.

The table summarises the research on each common concern, and how strong it is.

Concern	What research in healthy adults shows	Evidence strength	Check with your GP first if
Kidney function	Controlled studies, including some using more direct measures of filtration, have not found harm at 3 to 5g daily.	Strong	You have kidney disease or reduced kidney function, or take medicines that affect the kidneys.
Kidney blood tests	Creatine raises blood creatinine, which can make the calculated eGFR look lower than true kidney function.	Well established	You have regular kidney blood tests (tell your GP you take creatine).
Blood pressure and heart	Trials have not shown a consistent rise in blood pressure. Creatine is not a treatment for any heart condition.	Moderate	You have high blood pressure or a heart condition, or take diuretics or other heart medication.
Liver	Studies monitoring liver enzymes have not shown harm at standard doses.	Moderate	You have a liver condition.
Long-term daily use	Studies running up to around five years have not identified safety concerns, and there is no evidence that breaks are needed.	Moderate	You take regular prescription medication.
Pregnancy and breastfeeding	Human safety data are limited.	Insufficient	You are pregnant, trying to conceive or breastfeeding.

Does creatine damage your kidneys?

Research in healthy adults has not found that creatine damages the kidneys at standard doses of 3 to 5g a day. The worry grew out of a single case report and a misunderstanding of how kidney function is measured, not controlled trials.

Where the kidney worry came from

In 1998, a case report described a young man whose kidney function worsened while he was taking creatine.[2] What attracted fewer headlines was that he already had a pre-existing kidney condition.

The second source is chemistry. Each day, roughly 1 to 2 per cent of the body's creatine breaks down into creatinine, a waste product the kidneys filter out. Take more creatine and more creatinine is produced, so blood levels rise. On a blood test, that looks like a kidney problem even when there isn't one.

What controlled studies measured

The more useful studies therefore measured kidney filtration directly, using markers such as cystatin C or isotope clearance methods. In healthy adults taking standard doses, these studies have not shown a decline in kidney function, and systematic reviews pooling the trials reach the same conclusion.[3]

There is far less research in people who already have kidney disease, which is why anyone with reduced kidney function should speak to their GP before starting.

The creatinine blood test issue: what to tell your GP

If you take creatine, a routine kidney blood test may suggest your kidneys are working less well than they are. Telling your GP before the test, and knowing which test gives a clearer picture, avoids an unnecessary scare.

Standard checks use serum creatinine to calculate an estimated glomerular filtration rate (eGFR). A raised creatinine can signal reduced filtration, although muscle mass, hard exercise and a recent meat-heavy meal also push it up. In someone taking creatine, the kidneys may be filtering normally while the calculation reads the extra creatinine as a fall in function.

How each test is affected:

Test	What it measures	Effect of creatine	What to ask your GP
Serum creatinine	The level of creatinine, a muscle waste product, in the blood.	Usually raised, because more creatine is converted into creatinine.	Whether the result fits with taking creatine daily.
eGFR (estimated glomerular filtration rate)	Kidney filtration, calculated from serum creatinine, age and sex.	Can read lower than true kidney function.	Whether a lower reading needs a second test before conclusions are drawn.
Cystatin C	A protein filtered by the kidneys, used as an alternative filtration marker.	Not affected by creatine intake.	Whether a cystatin C test, or an eGFR based on it, would give a clearer picture.

What to say at your appointment

Mention creatine before the blood is taken. One sentence covers it: "I take 5g of creatine a day and have done so for about 6 months." Your GP can then read the result in context, and may suggest a cystatin C test if needed.

Creatine, blood pressure and heart health

Research in healthy adults has not shown that creatine raises blood pressure. The concern comes from creatine drawing water into the body, but most of that water is held inside muscle cells, where it is part of how creatine works, rather than in the blood vessels.

That water also explains the small early change on the scales some people notice, which is different from bloating. Our guides to creatine myths and water retention and creatine and bloating in women cover it in detail.

Creatine has been studied in people with heart conditions as a medical research question, but it is not a treatment for any heart condition. Anyone with high blood pressure or a heart condition, or taking medication such as diuretics, should check with their GP first.

Is it safe to take creatine every day, indefinitely?

Studies of healthy adults taking creatine continuously, some running for up to around five years, have not identified safety concerns at standard doses. No study can follow people indefinitely, but there is no evidence that daily use needs breaks or cycling off.

Those studies also monitored liver enzymes and general blood markers, without signs of harm at standard doses.

Supplementing does reduce how much creatine the body makes for itself, but research suggests this production returns once you stop, with no evidence of lasting suppression.

A loading phase (around 20g a day for five to seven days) is optional. A steady 3 to 5g a day fills muscle stores over three to four weeks, reaching the same end point more gently.[4] Our guide to how much creatine you need covers dose, timing and missed days.

Is creatine safe for women and over-50s?

Creatine's safety evidence is not limited to young male athletes. Trials have included women and adults over 50, and the conclusions above apply to both, Women do not need a different dose, and our guide to creatine for women explains what it does and who it suits.

Over-50s often come to creatine for muscle and strength. One of creatine's two authorised GB health claims states that daily creatine consumption can enhance the effect of resistance training on muscle strength in adults over 55, at 3g a day. The other covers physical performance in successive bursts of short-term, high-intensity exercise. These concern benefit rather than safety, and are the only benefits a creatine product can claim.

The practical difference with age is medication: older adults are more likely to take regular prescriptions, so a quick check with a GP or pharmacist first is sensible. Our guides to creatine after 50 and creatine and bone health after 50 go further.

Who should check with a GP first

Creatine's safety record applies to healthy adults. These groups should speak to their GP or pharmacist before starting:

Kidney or liver conditions: anyone with chronic kidney disease, reduced kidney function or liver disease.
Diabetes with kidney involvement: anyone with diabetic kidney disease or abnormal kidney test results.
Heart conditions or high blood pressure: especially anyone taking medicines that affect the kidneys, such as diuretics.
Pregnancy and breastfeeding: human safety data during pregnancy and breastfeeding remain limited.
Under-18s: creatine should only be used with professional guidance.
Regular prescription medication: anyone taking regular medicines, so possible interactions can be checked.

Important

This article is for general information only and is not medical advice. Speak to your GP or pharmacist before starting any new supplement, particularly if you have a medical condition, take regular medication, or are pregnant or breastfeeding.

Product quality: the overlooked safety factor

For a healthy adult, the bigger practical risk is often the product rather than the creatine. Independent testing has found contaminants and label inaccuracies in some creatine supplements, and a contaminated or underdosed product undermines everything the research says about creatine itself.

That is why third-party testing matters. Youth & Earth's Micronised Creatine Chews are made in a cGMP-certified facility and independently tested.. Our Youth & Earth manufacturing and testing deep dive explains what that covers, and the Creatine Chews deep dive sets out dose, format and ingredients. Our guide to how we approach safety for NMN applies the same thinking across the range.

Because creatine draws water into muscle, drink enough fluid through the day: the NHS suggests 6 to 8 glasses of fluid a day for most adults.

The bottom line

For healthy adults, the evidence on creatine monohydrate is unusually reassuring: decades of research, no sign of kidney, liver or blood pressure harm at standard doses, and no need to cycle off. The realistic risks sit elsewhere: a misread blood test, solved by telling your GP, and a poorly made product, solved by choosing one that is independently tested. If you have a kidney, liver or heart condition, are pregnant or take regular medication, start with a conversation with your GP.

Independently tested creatine

Youth & Earth Micronised Creatine Chews provide 5g of creatine monohydrate a day in two chews, made in a cGMP-certified facility with an independent Certificate of Analysis for every batch. If any of the conditions above apply to you, check with your GP before starting.

Explore Youth & Earth Micronised Creatine Chews

Frequently asked questions

Is creatine bad for your kidneys?

Research in healthy adults has not found kidney harm at 3 to 5g a day, including in studies measuring filtration directly. Creatine does raise blood creatinine, so anyone with existing kidney disease should speak to their GP first.

Can creatine affect a kidney function blood test?

Yes. Creatine raises blood creatinine, which is used to calculate eGFR, so kidney function can look lower than it really is. Tell your GP before the test; cystatin C is an alternative marker unaffected by creatine.

Should I stop taking creatine before a blood test?

Not necessarily. Tell your GP you take creatine so the result is read in context; they may suggest a cystatin C test or a pause if a clearer picture is needed.

Does creatine raise blood pressure?

Research in healthy adults has not shown that it does, and most of the water creatine draws is held inside muscle cells. Anyone with high blood pressure or taking diuretics should check with their GP first.

Is it safe to take creatine every day long term?

For healthy adults, studies of daily use lasting up to around five years have not found safety concerns at 3 to 5g a day, and there is no evidence you need to cycle off.

Is creatine safe if you're over 50?

Research including older adults supports the same safety conclusions at 3 to 5g a day. Because over-50s are more likely to take regular medication, a quick check with a GP or pharmacist first is sensible.

Who shouldn't take creatine without checking with a GP?

People with kidney or liver disease, a heart condition, high blood pressure or diabetes with kidney involvement should check first, as should anyone pregnant, breastfeeding, under 18 or on regular prescription medication.

References

[1] Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18. DOI: https://doi.org/10.1186/s12970-017-0173-z

[2] Pritchard NR, Kalra PA. Renal dysfunction accompanying oral creatine supplements. Lancet. 1998;351(9111):1252-3. DOI: https://doi.org/10.1016/S0140-6736(05)79319-3

[3] de Souza E Silva A, Pertille A, Reis Barbosa CG, Aparecida de Oliveira Silva J, de Jesus DV, Ribeiro AGSV, et al. Effects of creatine supplementation on renal function: a systematic review and meta-analysis. J Ren Nutr. 2019;29(6):480-9. DOI: https://doi.org/10.1053/j.jrn.2019.05.004

[4] Antonio J, Candow DG, Forbes SC, Gualano B, Jagim AR, Kreider RB, et al. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr. 2021;18(1):13. DOI: https://doi.org/10.1186/s12970-021-00412-w