What is creatine, and who is it actually for?

Creatine is a small compound built from three amino acids: glycine, arginine and methionine. Your liver, kidneys and pancreas make roughly one gram of it a day, and you eat another one to two grams if you regularly eat red meat and fish. Around 95 per cent of what you hold ends up in skeletal muscle, most of it in the form of phosphocreatine.

It is worth being clear about what it is not, because the category has spent three decades muddling this. Creatine is not a hormone and has nothing structurally in common with anabolic steroids. It is not a protein, and it is not a protein substitute. It is not a stimulant, so there is no lift twenty minutes after a glass and nothing to come down from. If you have avoided it because it sounded like something you did not want in your body, the honest answer is that it is already in your body and has been since before you were born.

The useful fact, and the one that explains why supplementing does anything at all, comes from the International Society of Sports Nutrition's 2017 position stand: on a normal mixed diet, muscle creatine stores sit only 60 to 80 per cent saturated. There is room in the tank. Supplementing fills it, typically raising muscle stores by 20 to 40 per cent.

That one number is the whole commercial case for creatine, and it is worth being blunt about what it implies. If a normal diet filled the tank, there would be no product here and we would not be selling one. What a creatine supplement does is close a gap that eating differently mostly cannot, because you would need roughly a kilogram of red meat a day to match a 5g serving. That is the argument. There is no second one, and anything a brand adds on top of it is decoration.

Every cell in your body runs on ATP, adenosine triphosphate. A cell holds only a few seconds' worth at a time, which sounds like a design flaw until you realise the point is not storage, it is turnover. ATP gets spent and rebuilt constantly, and the speed of that rebuild is what limits how hard a cell can work in the moment.

Phosphocreatine is the fast way to rebuild it. It sits in the cell holding a spare phosphate and hands it straight back to ADP the moment ATP runs short, with no waiting for food to be broken down. The reserve empties in seconds under hard demand and refills between efforts. How much you have stored decides how big that buffer is.

This is the part most articles skip, and it is the part that makes the rest make sense. Creatine does not have a long list of separate effects. It has one effect, in a lot of different places.

Any tissue with a high and spiky energy demand leans on the phosphocreatine system. A muscle contracting hard is the obvious one. The less obvious one is the brain, which is about two per cent of your body weight and uses around twenty per cent of your energy, in bursts, with very little local storage. That is why the same compound shows up in trials on leg strength and in trials on memory, and why the research keeps widening rather than fragmenting.

There is a real limit on the brain side and it deserves stating. The ISSN position stand is explicit that creatine uptake by the brain is slow and limited. Supplementing raises brain creatine by something in the order of 5 to 15 per cent, against 20 to 40 per cent in muscle. That is why the cognitive trials tend to use larger amounts over longer periods than a muscle trial would, and it is why the cognitive findings are newer and less settled than the muscle ones.

Creatine has one of the deepest evidence bases of any supplement sold in New Zealand, which makes it one of the few where the honest summary is more impressive than the marketing. Here is what the strongest studies found, in the words the researchers used, about the people who took part.

Muscle and strength, alongside resistance training. A 2017 meta-analysis pooled 22 randomised controlled trials covering 721 older adults with mean ages from 57 to 70. All of them were resistance training. The groups taking creatine finished with 1.37kg more lean tissue than the groups training on placebo, and gained more strength on chest press and leg press. Note what that number is doing: these were people at an age when lean tissue usually goes the other way. The authors open the paper on functional impairment, not on muscle gain, which is the frame that fits.

Memory. A 2023 review in Nutrition Reviews pooled eight randomised trials in healthy people and found memory improved against placebo. The interesting part is the split. In participants aged 66 to 76 the effect was large. In participants aged 11 to 31 it was indistinguishable from nothing. Dose, duration and sex made no difference to the finding; age did.

Cognition more broadly, and where it stops. A 2024 meta-analysis of 16 trials covering 492 adults found significant effects on memory, on attention time and on processing speed. It found no significant improvement in overall cognitive function or executive function. That is worth saying plainly, because it is the boundary of the claim: creatine has evidence behind specific cognitive measures, not behind a general sharpening. That paper's own subgroups leaned toward the 18 to 60 band, which sits in mild tension with the 2023 review. Neither is settled, and anyone telling you the brain research is finished has not read it. The full state of the cognitive evidence, including what happened when the most-quoted study was repeated, is worth reading before you buy creatine for your brain.

Bone, with training, over a long trial. Seventy adults with a mean age of 58 took creatine at 0.1g per kilogram or placebo while doing supervised whole-body resistance training three days a week for a full year. Bone area at the distal tibia and the tibial shaft was maintained or increased in the creatine group where the placebo group lost area. One-year supervised trials are rare and this one used a dose close to a normal daily serving.

This is the point where an article usually stops and a product page starts. It is more useful to show you the join, because the boundary above is the reason our tub reads the way it does.

Our label says daily energy and cognitive support. It could have said considerably more. Every one of the following was available to us, and every one was left off:

"Supports brain function." Broad, appealing, and not supported. The 2024 meta-analysis looked for exactly that and found no significant improvement in overall cognitive function. A claim we would lose an argument about is not worth the shelf space.

"Improves sleep." The sleep-deprivation trials are the most quoted creatine research on the internet right now and they measured performance during a shortage of sleep, not sleep itself. There is no creatine sleep claim to make, so we do not make one, even though it would sell.

"Builds muscle." True in the trials, and every one of those trials had people lifting something. A muscle claim that drops the training is a claim the buyer disproves on themselves in eight weeks, which is worse than no claim at all.

What survived is narrower and it is what the pack carries. We would rather explain the line than have a customer find it.

Function during a bad night. Two trials looked at cognitive performance under sleep deprivation rather than at sleep itself. One used 20g a day for a week before 24 hours without sleep, and found less decline in reaction time, balance and mood. A 2024 trial used a single large dose during about 21 hours of sleep deprivation and measured both better cognitive performance and changes in the brain's high-energy phosphates. Both used amounts far above a daily serving, and neither says anything about sleep quality, which creatine has no evidence for at all. If sleep itself is the problem, that is a different conversation.

Read the last section again and notice something about the people in it. Mean ages of 57 to 70. Participants aged 66 to 76. Seventy adults with a mean age of 58, training for a year. That is where the best creatine research has been done for the last decade.

Now picture who creatine gets sold to. Young men, in tubs the size of paint cans, next to pictures of people who lift for a living.

That gap is not a conspiracy and nobody was lied to. Creatine was researched first in sport, so sports nutrition companies got there first, built the packaging and the language around their own customer, and everyone else simply never got offered it. If you are a woman in your fifties who has never once considered creatine, that is not because you dismissed it. It is because nobody ever put it in front of you.

Which makes the research below new information rather than a correction.

Women start from a lower base. A 2021 review of creatine across women's health reported that women carry roughly 70 to 80 per cent lower creatine stores than men before any supplementation. The same review found benefits for strength before menopause, benefits for muscle size and function after it, favourable effects on bone alongside resistance training, and safety comparable to placebo. Lower starting stores mean the same serving closes a bigger gap, which is a large part of why the newer work has focused here.

There is a great deal more research in women specifically, covering muscle, bone and memory. The memory finding lives in the older group. That 2023 review did not find a general memory effect that happened to include older adults. It found the effect almost entirely in older adults, and essentially nothing in the young. The same is true of the muscle work: creatine helps a 25-year-old add strength, but it helps a 65-year-old hold onto something that is otherwise going away. Those are not the same thing, and the second one matters more.

None of which makes this a women's product or an over-fifties product. A 30-year-old man reading a properly made 5g monohydrate will find nothing here that excludes him, and the training research is his research. The point is narrower than that: the category decided who this was for before the evidence did, and the evidence has since gone somewhere else.

An article that only lists upsides is not worth reading. There are people for whom creatine does very little, and there is no point pretending otherwise.

If you eat a lot of red meat and fish, you are already running fuller. Dietary creatine comes almost entirely from animal foods, so a regular meat eater takes in one to two grams a day on top of what their body makes. They still sit below full saturation, but the gap is smaller and so is the change. The reverse is also true and it is the most reliable pattern in the literature: vegetarians and vegans start lower and tend to notice more. It is the same logic that makes what you eat the first place to look before any supplement.

Some people respond less than others. Baseline stores vary, muscle fibre composition varies, and a minority of people simply do not shift much. This is a known feature of the research rather than an excuse for it.

It works with activity, not instead of it. Every trial behind the muscle and strength findings paired creatine with resistance training. If you do nothing at all, creatine is not going to build you anything. What it can still do is top up an energy reserve that your brain and your muscles both draw on, which is a smaller and quieter claim than the one usually made for it.

Five grams a day is the standard maintenance serving and the simple default, but it was never meant to be a ceiling. The ISSN position stand puts maintenance at 3 to 5g a day and notes that larger people may need 5 to 10g a day just to keep stores topped up. A more useful anchor than a fixed number is roughly 0.1g per kilogram of bodyweight, which is about 6g for a 60kg adult and closer to 9g for a 90kg one. We take the same view of magnesium dosing, and for the same reason: a single number on a label was never going to fit a 58kg woman and a 110kg man equally well.

Loading, meaning about 20g a day split into four doses for five to seven days, fills your stores in roughly a week instead of three to four. It is optional. Skipping it gets you to the same place more slowly and is easier on your stomach.

That is the summary. The full version, including what to adjust for, what the first month feels like and the small habits that make a measurable difference, is in how to get the most from your creatine.

Creatine has been studied for longer and in more people than almost anything else on a supplement shelf, which means the safety question has better answers than most. The ISSN position stand reports up to 30g a day for five years as safe and well tolerated in healthy individuals. That is six times a standard serving, for five years.

Two things are still worth knowing.

Creatine will make a routine kidney test look worse than it is. Most kidney screening is calculated from blood creatinine, and creatine raises blood creatinine as a normal consequence of how it is processed. A 2026 review of 26 studies covering 1,036 participants found exactly that pattern: serum creatinine up, estimated filtration rate down when calculated from creatinine, and no change at all when kidney function was measured a different way. The authors read it as altered creatinine metabolism rather than kidney damage. The practical takeaway is simple: tell your doctor you take creatine before a blood test, so nobody misreads the result and chases something that is not there.

A small rise on the scale early on is water inside muscle. In one trial, a week of high-dose creatine raised total body water by about two per cent, which registered on body scans as one to two kilograms of extra fat-free mass. Note the dose: that was a loading protocol at roughly four times a normal serving. On a single daily serve, expect less. It is water in the muscle cell rather than fat, it is part of the mechanism rather than a side effect of it, and it settles. The rest of the side-effect questions, including hair loss and what to tell your doctor before a blood test, are answered separately.

Biosphere had no creatine for the first several years. Adding one meant answering a question we could not answer at the time: what would ours be, other than another white tub in a category with a hundred of them. Here is our co-founder Andrew on what changed, and on the part of it we are not going to dress up.

Monohydrate is the form nearly every study on this page was built on, so using anything newer would have meant trading the evidence base for a marketing angle. The decision worth defending is not the molecule. It is paying more for a version of it people will still be taking in week three. That reasoning runs through how we think about absorption across the range, and it is why Biosphere Creatine costs what it costs. If you are comparing tubs, what actually differs between one creatine and another is a shorter list than the packaging suggests.