Creatine dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Creatine is one of the most studied supplements there is. It clearly boosts strength. Its effect on muscle size is smaller than the ads say, and a European regulator has rejected the claim that it helps thinking.
Evidence grade for Creatine: Moderate. The rule: at least one finished study in people, and at least 100 people who took it. The sum on this page: 3 completed trials, 168 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 168
- Human studies
- 3
- Found nothing
- 2
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
3 completed trials, 168 people given it
5 effects reported, 3 unwanted, 2 wanted, by people using it, not a trial
Goal pages: Muscle and strength, Brain, memory and mood, Skin, hair and appearance, Bone and joints
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Creatine helps your muscles push harder for a few more seconds. Your body makes it and you eat it in meat. It is the most studied supplement there is. It makes you stronger, and that part is settled. It is sold as a supplement. It is not a drug and does not need to be.
What people take it for
- Getting stronger.
- Bigger muscles.
- A sharper brain and better memory.
- Holding on to muscle as they get older.
What studies in people showed
Strength is the claim that holds. Hundreds of trials say it makes you stronger and lets you do more work in a session. Muscle size is smaller than the ads say. When you scan the muscle itself instead of the whole body, the effect is small and might be zero. Brain is a no on current evidence. The biggest trial had 123 people and found no benefit, with more side effects on creatine. The European food regulator looked at a company's own file and rejected the brain claim. Hair loss rests on one study of 20 rugby players. It measured a hormone and never looked at hair. A later 12 week trial in 45 men then measured hair and hormones. Thirty eight finished. Nothing moved. Kidneys: a 12 week trial in lifters on a high protein diet found no change in kidney filtration. And you do not need to load. Three grams a day gets you there in about four weeks.
What people report
Reports, not study results
The good
- Stronger lifts and a couple more reps within a few weeks.
- Cheap, and almost nobody has to stop because of side effects.
The bad
- Water weight in the first week or two. It goes into the muscle, not under the skin, and it is near universal.
- Stomach upset at loading doses. It goes away at three to five grams a day.
- Hair loss worry. It is everywhere on forums and makes people quit, and it rests on one unrepeated study that never measured hair.
Where these come from: Strength training forums and supplement communities for the water and stomach reports. The side effect count in the brain trial is from that trial's own tables.
My bottom line
This is the real thing. It has the strongest evidence of anything in this category. Three to five grams of plain monohydrate every day, whether or not you lift.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Creatine has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Memory and thinking123 people · 1 study
- Hairno headcount stated · 1 study
What people using it report
Real people telling you what happened to them. Nobody checked it, and the people who post are not a fair sample, so it cannot prove anything works. It is still the best guide on this page to what people actually do with Creatine, what they expect, and what goes wrong. The full account, including the negative reports, is below.
33 of the 36 indexed goals have no study of any kind behind Creatine
No study in people, animals or cells on this page reports a result for these. That does not prove Creatine does nothing for them. It does mean anything you have heard about Creatine and one of these did not come from a study cited here.
When this earns a spot
It matters because many studies in people show gains in strength and lean mass, and its safety record in healthy people is unusually clean. It is the one basic item that does not depend on a blood test. It is not a kidney tonic, and you do not wait for a shortage to take it.
Aaron's list, tier 1
Bloodwork that belongs beside the bottle
Kidney function (eGFR) is optional background, not a reason to start or stop for healthy people. Tell your doctor before the blood draw.
Test again after about 90 days. If that blood number did not move, stop.
- Creatinine often rises a little. That can look like kidney trouble if nobody writes down that you take creatine.
Reading the number
There is no creatine blood target to chase. If creatinine jumped and you started creatine, say so. Your doctor can order another kidney test, cystatin C, when the picture is unclear.
What these tests mean: BMP electrolytes.
What people typically order
A basic metabolic panel is enough. You do not need a special creatine panel. Buy plain creatine monohydrate, not a branded blend built around it, if you buy it at all.
Show full evidence
What is Creatine?
Creatine is one of the most studied supplements there is. It clearly boosts strength. Its effect on muscle size is smaller than the ads say, and a European regulator has rejected the claim that it helps thinking.
Creatine is made by your body and also comes from meat. Muscle stores it and uses it to refill its fast fuel, called ATP, during short, hard efforts. Its effect on strength, and on how much work you can do, is real and very well tested in people. Two claims are weaker than the marketing says. When muscle growth is measured by scanning the muscle itself, rather than the whole body, the pooled effect is small and might be zero. And the claim that it helps thinking, which now sells a lot of it to older adults, was checked by the European Food Safety Authority at a creatine maker's request. The regulator ruled that the claim was not proven.
How does Creatine work?
It fills muscle with phosphocreatine, which refills ATP, the muscle's fast fuel, during hard efforts that last a few seconds. That lets you do more work each session. Most of the strength gain likely comes from that extra work over months, not from creatine building muscle directly.
What have studies in people found about Creatine?
Huge. Hundreds of studies in people, which is rare on this site. The question is not whether there is data. It is what the data shows once you split the results apart.
- Strength and hard work capacity: better, again and again, across decades of studies. This is the claim that holds.
- Muscle size: when the muscle is scanned directly, rather than the whole body, the pooled effect is small and may be zero.
- Thinking in healthy, rested adults: the largest study, in 123 people, found no benefit. The European regulator rejected the claim, using a maker's own file.
- Hair: a 2025 study that did measure hair and male hormones in 45 men found no difference between the groups. The 2009 hormone study never measured hair.
- Kidneys in healthy people: a 12-week study in lifters on a high-protein diet found no change in kidney filtering. No study has shown harm in healthy people.
- Loading is optional. Three grams a day fills muscle just as full in about four weeks as twenty grams a day does in six days.
What this does not tell you: Nearly every positive review in this area has authors with industry ties. The papers say so, and it is worth knowing. The strength effect holds up anyway. The muscle size and thinking claims are where the gap between the ads and the measurements is widest.
What do people who took Creatine report?
This is what real people say happened to them, good and bad. Nobody measured it. A report cannot tell a real effect from the lift people get just from expecting it to work, from a diet or training change made at the same time, or from what was really in the vial. We still put it near the top. It is the next best thing to a study in people: what happens when real people use it, including what goes wrong.
- Water gain in the first week or two is almost universal. The water goes inside the muscle cells, not under the skin.
- Stomach upset is common at high loading doses and usually goes away at three to five grams a day.
- Worry about hair loss is widespread in forums and makes many people stop. The 2009 hormone study never measured hair. A 2025 study that did measure hair found no change.
Sources: Strength training forums and supplement communities. Uncontrolled self-report, included for expectations rather than as evidence.
The state of the research
Creatine is a rare case on this site. The problem is not missing studies. It is that a large, truly positive body of research has been stretched to cover claims it does not support. The strength evidence is strong enough to justify creatine on its own. The muscle size effect shrinks when you scan the muscle directly instead of guessing from a whole-body scan. The thinking claim was tested by a regulator, at a maker's own request, and failed.
The hair loss story is the mirror image. It spreads as fact, but for years it rested on one study of 20 rugby players that measured a hormone ratio and never looked at anyone's hair. A 2025 study that did measure hair and male hormones found no change. Believing the hair claim now means ignoring that result. That is the same mistake as believing the overclaims, just pointed the other way.
The evidence, in charts
Fig. 1a · how many people
168people, across 2 studies in people cited here
| Study | People | Share |
|---|---|---|
| BMC Medicine 2023 | 123 | 73% |
| Journal of the International Society of Sports Nutrition 2025 | 45 | 27% |
One study holds 73% of these people, so the total rests more on one study than its size suggests. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 2 more studies in people give no headcount and are not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
4 of 6 sources here are studies in people. The rest are not.
- Study in people · done in people467%
- Review of studies · sums up other studies233%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 5 different years, 2009 to 2025, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Supplement
- Molecule weight
- 131.1 Da
- Half-life
- About 3 hoursShort, 1 to 6 hours
- Chain length
- None on file
Half-life as stated on file: About 3 hours in plasma; muscle stores deplete over roughly 4 to 6 weeks after stopping
No amino acid sequence is on file for Creatine, which is expected: a supplement is not built from amino acids.
The studies we cite
- Study in people2023The effects of creatine supplementation on cognitive performance: a randomised controlled study
Creatine did nothing for thinking, and it caused more complaints than the dummy did. 123 people took part, about half of them vegetarian. Tests of mental performance came out the same whichever they were given. More of the people on creatine reported side effects than the people on the dummy. Creatine has good evidence behind it for training. This is the trial that tested the brain claim, and the brain claim did not survive it.
123 participants, roughly half vegetarian. The trial reports no cognitive benefit, with more side effects in the creatine arm than placebo.
- Study in people2009Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players
The whole creatine causes hair loss story rests on one small study that never looked at hair. 20 college rugby players took creatine for three weeks. Their blood showed a shift in the balance between two male hormones. Nobody counted a single hair. Nobody followed the players afterwards. And no other team has got the same result in the years since. That is the entire evidence base for a claim repeated everywhere.
The single study behind the entire creatine and hair loss claim. It measured a hormone ratio in 20 rugby players over three weeks. It did not measure hair.
- Study in people2025Does creatine cause hair loss? A 12-week randomized controlled trial
The first study that actually looked at hair found nothing. 45 men who lift weights took 5 grams of creatine a day, or a dummy powder, for 12 weeks. 38 finished. Male hormone levels did not differ between the groups. Neither did hair density or thickness. The 2009 hormone study is no longer the last word, and the last word is that nothing changed.
45 resistance-trained men aged 18 to 40 randomised to 5 g/day creatine monohydrate or maltodextrin for 12 weeks. 38 completed. Androgens and hair measures did not change between groups.
- Study in people2013Does long-term creatine supplementation impair kidney function in resistance-trained individuals consuming a high-protein diet?
Creatine did not harm kidneys in lifters who already ate a lot of protein. They took a loading dose and then 5 grams a day for 12 weeks, or a dummy powder. Kidney filtering, measured with the most accurate tracer test, did not change. This is 12 weeks in healthy lifters, not a lifetime in people with kidney disease.
12-week randomised trial in resistance-trained adults eating at least 1.2 g/kg/day protein. Creatine 20 g/day for 5 days then 5 g/day. Glomerular filtration by 51Cr-EDTA clearance did not differ from placebo (group x time p = 0.64). NCT01817673.
- Review of studies2023The effects of creatine supplementation combined with resistance training on regional measures of muscle hypertrophy: a systematic review and meta-analysis
This review pooled studies that scanned the muscle directly. The extra muscle growth from creatine was small, and it might be zero. The effect leaned toward younger adults, the opposite of how creatine is sold for ageing.
When hypertrophy is measured by direct site-specific imaging rather than whole-body composition, the pooled effect is small with a credible interval crossing zero. The age moderation runs toward younger adults, which is the opposite direction to how creatine is marketed for ageing.
- Review of studies2024Creatine and improvement in cognitive function: evaluation of a health claim pursuant to article 13(5) of regulation (EC) no 1924/2006
This is a regulator's ruling, not a new study. The European Food Safety Authority looked at a file from a creatine maker claiming it helps thinking. It found the claim was not proven.
The European Food Safety Authority assessed the cognition claim on a dossier submitted by a creatine manufacturer and concluded a cause and effect relationship was not established.
Common questions
Has Creatine been tested in people?
Yes. 168 people given it across 3 completed trials cited here, 2 of which found nothing. Creatine is one of the most studied supplements there is. It clearly boosts strength. Its effect on muscle size is smaller than the ads say, and a European regulator has rejected the claim that it helps thinking.
What is the Creatine dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 3 completed trials, 168 people given it
Is Creatine FDA-approved?
Sold as a dietary supplement. Not an approved drug for any use.
Does creatine build muscle?
It reliably improves strength and how much work you can do in a session. Its direct effect on muscle size is smaller than usually claimed. When growth is measured by scanning the muscle itself, rather than the whole body, the pooled result is small and may be zero.
Does creatine help cognition?
Not in healthy, rested adults, going by current evidence. The largest study found no benefit, and the European Food Safety Authority rejected the claim, using a file sent in by a creatine maker. Any hints of benefit have come from people short on sleep and from vegetarians.
Does creatine cause hair loss?
The claim started with one study of 20 rugby players that measured a hormone ratio and never looked at hair. A 12-week study in 45 men later measured both hormones and hair. Thirty eight finished. Nothing changed. That is a thin basis for a belief this widespread.
Do I need to load?
No. Three to five grams a day fills your muscles in about four weeks. Loading gets you there in under a week, but it causes more stomach upset. Both end up in the same place.
Is monohydrate worse than the expensive forms?
No study has shown any form beats monohydrate on a real health result. Monohydrate is the form nearly all the research used, and it is the cheapest.