Creatine, brain health, and your blood test results

Creatine is among the most heavily researched supplements in the world. The Australian Institute of Sport places it in Group A, the tier reserved for supplements with strong scientific support for use in specific situations under appropriate guidance.¹

Most of the recent attention has been about creatine and brain health rather than muscle, prompted by an Alzheimer’s trial published in 2025. If you have read about that and wondered what it means, this article sets out what the research has established so far and where it currently stops.

And if you already take creatine, it is always helpful to share this with your GP, as it can change how a routine kidney blood test should be interpreted.

• The evidence behind creatine for exercise and muscle is strong.
• Brain research has established that supplementation raises creatine levels in the brain. Whether that improves cognition is still being tested.
• Plain creatine monohydrate has the strongest evidence and is usually the cheapest option on the shelf.
• If you take it, tell your GP because it affects how one of your blood tests will read.

In this article

• What creatine is
• The brain health research
• Why it affects your kidney blood test
• What your GP may check
• Who should ask a GP first
• Choosing a product
• Where this leaves you

What creatine is, and what it is established for

Creatine is a compound your body already makes, mostly in the liver, and which you also get from meat and fish. Around 95% of it is stored in skeletal muscle, where it helps regenerate energy during short, intense efforts.

For exercise, the evidence base is substantial. The International Society of Sports Nutrition describes creatine monohydrate as the most effective nutritional supplement currently available for increasing capacity during high-intensity exercise and building lean mass during training, and reports that long-term use at standard doses is well tolerated in healthy people.² Sports Dietitians Australia publishes a public fact sheet on it.³

Brain health: what the research has established

The brain uses creatine as well as the muscle does. Researchers have been working on two questions. Can taking it orally raise brain creatine levels, and if so, does that change how the brain functions?

The first question now has an answer. A trial at the University of Kansas, published in Alzheimer’s & Dementia: Translational Research & Clinical Interventions in May 2025, gave 20 people with Alzheimer’s disease 20 grams of creatine monohydrate a day for eight weeks. Brain total creatine rose in 85% of participants, by an average of around 11%.⁴ The researchers also recorded improvements in working memory and executive function. A follow-up paper in 2026 examined markers of cellular energy production in the same participants.⁵

Oral creatine reaching the brain in a group where that had not been demonstrated is a genuine result, and it is the reason the study attracted attention.

The second question is where the research currently sits. The trial was designed to test whether the approach was feasible rather than whether it worked. Twenty participants, eight weeks, and no placebo or comparison group, which means the improvements in cognitive scores cannot be separated from practice effects on repeated testing or from normal variation. The authors say this directly and identify randomised controlled trials as the next step.⁴ Those trials are underway.

So there is evidence that creatine gets into the brain; the early signals were interesting enough to justify larger trials, and those trials have not yet been reported. Although it is promising, creatine is not yet an approved treatment for dementia in Australia. However, as the supplement is readily available and has been extensively studied in other areas, it has strong appeal for many mature patients, and for this reason we recommend that you share with your GP whether you are taking creatine supplementation and the dosage.

Creatine vs creatinine: the blood test problem

This part applies whether you take creatine for training, for brain health or for something else entirely.

Creatine and creatinine are two different things with confusingly similar names. Creatinine is the waste product left over when creatine breaks down. Your body converts a small, fairly steady proportion of its creatine pool into creatinine every day, and your kidneys clear it.

Because that clearance is so reliable, creatinine is the basis of the standard kidney test. Your eGFR, or estimated glomerular filtration rate, is not measured directly. It is calculated from your blood creatinine level, along with your age and sex.⁶ The result is used by your doctor to establish how well your kidneys are working. However, if you supplement with creatine, you increase the size of your body’s creatine pool. A bigger pool produces more creatinine, and a higher blood creatinine level, which can affect the equation and make it look like there is an issue with the kidney, even though your kidneys are filtering just as well as before.

This is recognised in Australian pathology guidance. St Vincent’s Pathology in Sydney lists creatine supplements among the dietary factors that make eGFR results less accurate, alongside vegetarian and high protein diets.⁷

What tends to happen next if you haven’t informed your GP you are supplementing with creatine could be entirely avoidable: an unexpected result on a routine blood test, an anxious few days, a repeat test, sometimes a specialist referral, all of it triggered by a supplement rather than a kidney problem.

So the fix is simple. Tell your GP you take creatine.

What your GP might look at

Everyone’s situation is different, and what your GP suggests will depend on your age, health history and what prompted your interest in creatine. But the conversation commonly covers:

A baseline before you start. A creatinine and eGFR reading taken before you begin is far more useful than one taken afterwards, because it gives your GP a reference point. If a later result looks lower, they can see whether anything has genuinely changed.

Urine albumin to creatinine ratio (UACR). This looks for actual signs of kidney damage rather than estimating filtration, and it is a standard part of kidney assessment in Australian general practice.⁸

Blood pressure. Creatine draws water into muscle cells, so your GP may want a reading if blood pressure is already something you are monitoring.

Cystatin C, in some circumstances. Cystatin C is an alternative marker of kidney function that is not influenced by muscle mass or creatine intake, and it is occasionally used when a creatinine result is thought to be misleading. It is not part of routine testing in Australia and availability and cost vary, so it is a question for your GP rather than something to expect as standard.

Whether something else explains how you are feeling. This is the one clinicians care most about. Many people reach for creatine because of fatigue or brain fog. Those symptoms may have common, treatable causes: iron deficiency, low vitamin B12, an underactive thyroid, sleep apnoea, poorly controlled diabetes, depression. Investigating those first is the actual medicine. A supplement cannot fix a problem it is not addressing.

Your current medications. Some medicines are dosed according to kidney function, and some combinations warrant closer monitoring. Your GP is the person with the full picture.

Who should speak to a GP before starting

Talk to your doctor first if you:

• have existing kidney disease, a single kidney, or diabetes affecting your kidneys
• take medicines dosed according to kidney function, or regularly take medicines such as ibuprofen or naproxen
• have a liver condition
• live with bipolar disorder
• are pregnant or breastfeeding
• are under 18
• are considering the higher doses used in research studies rather than the smaller amounts typical for exercise

The Alzheimer’s trial used 20 grams a day, several times the amount typically used for training. Higher doses can mean more gastrointestinal upset and a larger creatinine load, which feeds back into the blood test issue. Participants in that trial took the dose under medical supervision, with monitoring throughout.

A note on what you are buying

In Australia, creatine powder is regulated as a food, not a medicine. Since 30 November 2023, sports supplements presented as tablets, capsules or pills that make performance claims are regulated as therapeutic goods and must be listed on the Australian Register of Therapeutic Goods. Products in traditional food forms such as powders, drinks and bars are not covered by that declaration.⁹ Therefore, it is important to note that the rules around labelling of creatine, as a food product, do not involve the same strict testing as medications.¹⁰

Which form is the most researched?

Walk into any supplement shop, and you will find creatine sold as monohydrate, hydrochloride, ethyl ester, buffered creatine, magnesium chelate and several proprietary blends, usually at very different prices.¹¹¹²

Creatine monohydrate is the most extensively studied form, and the International Society of Sports Nutrition states in its position stand that no alternative form has been shown to be superior.²

How to find the right brand?

There is evidence that some creatine manufacturing is not as tightly controlled and can lead to residues or contamination.¹³ Helpfully, there is a published benchmark to measure a product against. The European Food Safety Authority has set out specifications for creatine monohydrate: no more than 100 mg/kg of creatinine, no more than 50 mg/kg of dicyandiamide, dihydrotriazine not detectable, and heavy metals no more than 10 mg/kg.¹⁴

What about German versus Chinese creatine? You will see a lot written about this. It is worth noting that the majority of the world’s creatine is produced either at a single facility in Germany or at a small number of plants in China, so the question is a real one. But there is no published study comparing the two by country of manufacture, and most of the content arguing the point is produced by companies selling the more expensive option.

A more useful question than where it was made is whether the manufacturer will show you the numbers. A reputable supplier will provide a certificate of analysis listing actual impurity results, not simply a claim of high purity on the tub. A supplier who will not provide one has not given you a way to check.

One thing worth understanding about batch testing. In Australia, supplements can be certified by HASTA, which screens each batch for more than 250 substances prohibited in sport. That is valuable if you compete. But HASTA is explicit that its testing covers prohibited substances only, and that it does not verify other claims on the packaging, including ingredients or nutritional content.¹⁵

So a batch testing seal means the product should not cause a failed drug test. It is not a guarantee of purity or label accuracy. Those are separate assurances, and they are easy to confuse.

Sport Integrity Australia publishes guidance on creatine, and its free Sport Integrity app lists batch-tested supplements sold in Australia.¹⁶

What to look for on the tub

• Creatine monohydrate as the only active ingredient, rather than a proprietary blend
• A batch or lot number printed on the container
• A supplier who will provide the certificate of analysis for that batch on request, showing actual measured figures rather than a general claim of high purity
• Results that sit within the EFSA specification above
• A HASTA or equivalent batch testing mark if you compete in a sport that tests, remembering that this covers prohibited substances rather than purity

The batch number matters more than it looks. A certificate of analysis only tells you something if it refers to the batch you are actually holding.

Where this leaves you

If you take creatine for training, mention it to your GP so your kidney results are read against the right baseline, and buy from a supplier willing to show you what is in the tub.

If you started because of the brain health research, the position is that the science is at an earlier stage than the coverage suggests, not that it has been disproved. Supplementation does raise brain creatine. The larger trials are running. Taking a well studied, inexpensive supplement while that plays out is a reasonable choice to make, provided you are not treating it as a treatment for dementia, because it is not one. Make sure to remember to mention to your GP that you are taking it.

If you are deciding whether to start, it depends what you want from it. For strength and training the evidence is strong. For memory, it is still early days. And if the thing actually prompting the question is tiredness or difficulty concentrating, that is worth investigating in its own right first, because iron deficiency, thyroid problems, sleep apnoea, low vitamin B12 and depression all produce those symptoms and all have treatments.

Whichever applies, the one useful thing is to mention it at your next appointment. It takes a sentence and means that a routine result does not turn into an unnecessary investigation.

To talk through creatine or arrange a health check, book an appointment with your local Qualitas Medical Practice GP.

This article is general information only and is not a substitute for individual medical advice. Speak with your GP about your own circumstances.

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