Creatine monohydrate: what it does, who it helps, and what it can't do

The evidence-led answer

The short answer

If you do resistance training, taking creatine monohydrate tends to add a little on top of what training alone gives you: slightly more strength, and a small increase in muscle size. The effect is real but modest, and it is an add on to training, not a substitute for it. In healthy adults, the doses people normally use have not been shown to harm the kidneys or cause the problems creatine is often blamed for. You do not need it to make progress, and you do not need an expensive version of it.

What creatine is

Creatine is a compound your body already makes (mainly in the liver and kidneys) and that you also get from meat and fish. Most of it is stored in muscle, where it helps recycle the molecule muscles use for very short, hard efforts. Supplementing raises the amount stored in muscle, which is the mechanism thought to underlie its effects on training. Creatine monohydrate is the original, most tested form. It is a food supplement, not a medicine.

What the evidence shows for strength and muscle

When creatine is added to a resistance training programme, reviews of randomised trials find a small advantage over training with a placebo, for both strength and muscle size. The people studied include trained and untrained adults, older adults, and women. In postmenopausal women, a 2026 pooled analysis found small gains in lean mass (about +0.37 kg) and leg press strength when creatine (5 g/day or more) was combined with resistance training, with no measurable effect on bone density and no change in kidney markers. Two honest caveats: the effect sizes are small, and not everyone responds the same way.

Two pooled analyses of short duration strength tests put a number on this: a small effect for lower limb exercises such as the squat and leg press (effect size about 0.24, across 60 trials) and a similar small effect for upper limb exercises such as the bench press (effect size about 0.32, across 53 trials). A separate pooled analysis that used direct imaging, MRI, CT or ultrasound, rather than scales or a DXA scan, found a much smaller hypertrophy effect (about 0.11) whose confidence interval crosses zero, so that particular imaging based estimate is less certain than the strength result, though it points the same direction and was larger in younger adults. These two strength estimates were checked against the Lanhers 2015 and 2017 abstracts, not the full methods. Their full-text appraisal and funding declarations remain outstanding.

In older adults specifically, pooled trials find roughly a kilogram more lean tissue and moderate gains in chest and leg press strength over training with a placebo. Not everyone responds the same way: a small randomised trial found that vegetarians, who tend to start with lower muscle creatine stores than people who eat meat, gained more muscle creatine and more from training when they supplemented, compared with people who eat meat given the same protocol. Baseline muscle creatine and diet are one real reason some people respond more than others. A newer 2026 trial in vegans found the same direction for body composition and lower body power over four weeks (more muscle, less fat, better jump height with creatine), though it did not find a significant extra strength benefit specifically, so this is a real but still developing picture rather than a settled one. Both dietary-pattern trials were small (42 participants in the vegetarian trial and 20 in the four-week vegan trial), so they do not settle how diet changes response. The vegan trial’s own funding and conflict declarations have not been read. One author also appears on other creatine papers with disclosed industry relationships; that does not establish this trial’s funding.

Is it safe?

Kidneys

In adults without kidney disease, the doses people normally use have not been shown to harm kidney function. A position stand reports that supplementation up to 30 g/day for 5 years has been well tolerated in healthy people, and a review focused on renal safety concluded that creatine at 5 to 30 g/day appears to have no detrimental effects on kidney function of individuals without underlying renal diseases. This does not extend to people who already have kidney disease or reduced kidney function.

Two more recent pooled analyses of randomised trials, published in 2025 and 2026, reached the same conclusion using more direct kidney measures: a small rise in serum creatinine, but no significant change in urea or in estimated glomerular filtration rate. One of the two states plainly that it received no funding and its authors have no competing interests, and all its authors work in a kidney research centre with no stated tie to the supplement industry, which is a stronger basis than shared affiliation alone, though a paper's own declaration is not the same as independent verification. The other could not be checked in full this pass because it sits behind a paywall, so its own funding and competing interest declarations are unread and its independence from industry is simply unknown.

The blood test catch

Creatine breaks down into a waste product called creatinine, the same thing a routine blood test measures to estimate kidney function. Taking creatine can nudge that number up without your kidneys working any less well: a two year trial found serum creatinine rose in the creatine group while more specific kidney markers such as cystatin C stayed normal. If you take creatine and have a blood test, tell whoever ordered it, do not stop the test.

Other common worries

• Creatine is not an anabolic steroid and appears on neither the official 2026 WADA Prohibited List nor the 2026 Monitoring Program. Tested athletes should still manage supplement-contamination risk; batch testing reduces but does not eliminate it.
• Some of the early weight gain is water held inside muscle cells; the evidence describes this as modest, and it is not the same as gaining fat.
• Controlled evidence has not shown that creatine increases cramping or dehydration risk.
• The hair-loss concern began with a small 2009 hormone study that did not measure hair. A 2025 twelve-week trial directly measured hair outcomes in 38 completing resistance-trained men and found no difference between 5 g/day of creatine and placebo. That is reassuring but cannot exclude small or long-term effects or generalise to all populations.

Who funds this research?

It is worth saying plainly, because it affects how much weight to put on some of the reassurance above. A good part of the creatine efficacy and dosing evidence, including the main safety position stand, comes from a recurring group of researchers who have disclosed financial ties to the creatine industry, mostly to AlzChem, the manufacturer behind the Creapure brand, and to the International Society of Sports Nutrition. Read from their own published declarations rather than guessed from affiliation: the position stand behind much of this article's dosing and safety information was itself funded by a supplement trade body, and several named authors across that stand and other sources here, including the single trial on hair loss, have disclosed paid advisory, consulting or research relationships with creatine sellers. One 2026 study even carries a formal declaration of no conflicts while its own text separately discloses that a creatine manufacturer paid its publication costs and that a co author chairs a manufacturer supported advisory board, which is a useful reminder that a clean sounding declaration is not the same as a fully independent one. None of this means the findings are wrong. Not every source here shares this industry link: the kidney safety analysis by Naeini 2025, the strength and lean tissue analysis by Chilibeck 2017, and the cognition analysis by Xu 2024 declare no competing interests in their own published statements. Xu’s review reports funding from the National Natural Science Foundation of China. A paper's own declaration is not the same as an independent audit of it, and a clean declaration on one of those three questions says nothing about the other two. It does mean a reader deserves to know how concentrated the authorship and funding are in parts of this literature, rather than reading terms like 'position stand' or 'no conflicts declared' as proof of independence.

If you do take it

• Form: plain creatine monohydrate. Advanced forms (hydrochloride, buffered, liquid) cost more and have not been shown to work better.
• Dose: around 3 to 5 g per day.
• Loading: optional. A loading phase fills muscle stores faster; skipping it just means it takes a few weeks longer to reach the same place.
• Timing: taking it at a consistent time matters more than a specific time relative to training.
• The buy nothing version: a supermarket own brand creatine monohydrate that meets a recognised purity standard does the same job as a premium tub.

What about brain benefits?

Creatine's cognitive benefits are not established. Some reviews report memory benefits, but EFSA identified double-counting of participants in Xu's pooled analysis and did not accept it as support for the proposed cognition claim. Its 2024 assessment found that the submitted evidence did not establish a causal cognitive benefit. This does not prove that nobody could benefit, but it prevents us from presenting the pooled memory result as a settled benefit or an NST-endorsed moderate-confidence finding. Xu's 2025 correction clarifies attention and processing-speed scores; it does not resolve that separate statistical criticism. On this evidence, brain-benefit claims are not a sound reason for a healthy younger adult to start taking creatine.

The authors of the earlier memory review also corrected their analysis. Its overall result was no longer statistically significant, while a signal remained in older adults. They cautioned that the older-adult finding involved limited participant numbers and needed further trials.

Who should check with a clinician first

This is general information, not medical advice. Speak to a doctor or pharmacist before using creatine if you have kidney disease or reduced kidney function, a single kidney, are pregnant or breastfeeding, are under 18, take medicines that affect the kidneys, or have a chronic health condition. Severe or one-sided muscle pain, unexplained swelling or dark urine requires urgent medical assessment regardless of creatine use; simply stopping a supplement is not a substitute for assessment.