Walk into any Holland & Barrett on a Saturday afternoon and you'll see it happening: someone in gym kit picking up a tub of creatine monohydrate, checking the label, putting it back, then picking up a different tub with "advanced" or "elite" printed across the front instead. Creatine has quietly become one of the best-selling supplements in Britain — and also one of the most misunderstood. It's not a steroid, it's not a stimulant, and most of what's written about it online swings between two extremes: dismissed as "just for bodybuilders" or oversold as some kind of cognitive enhancer that will fix your memory and your squat in the same week. Neither extreme holds up particularly well once you look at what's actually been measured. Creatine is one of the most studied supplements in sports science, with a research trail going back to the early 1990s and hundreds of controlled trials behind it. The evidence for what it actually does — and doesn't do — is unusually settled for something sold next to protein shakes and pre-workout powder that make far bigger promises with far less backing them up.
What creatine actually does in the body
Creatine is a compound your liver, kidneys and pancreas already make from amino acids, and you also get it from red meat and fish. It's stored mostly in skeletal muscle, where it helps regenerate ATP — the molecule your muscles burn for short, explosive effort. Supplementing raises the amount of stored creatine (specifically phosphocreatine) available for that process, which is why the clearest, most repeated finding across decades of trials is improved performance in short, high-intensity bursts: sprinting, heavy lifting, repeated jumps, anything under about 30 seconds of maximal effort.
What it doesn't do is improve endurance performance in any meaningful way — a two-hour club run or a long turbo session won't benefit from it, and some athletes report feeling slightly heavier in the first week or two because creatine pulls water into muscle cells. That's not "bloating" in the way people mean when they complain about it; it's intracellular water, and it's part of how the compound works, not a side effect to fear.
The loading phase is optional, not mandatory
Most tub instructions still print a "loading phase": 20g a day, split into four doses, for five to seven days, followed by a 3–5g daily maintenance dose. This isn't wrong, but it's not necessary either. Loading saturates muscle stores faster — useful if you've got a competition or a specific training block coming up in under two weeks — but a flat 3–5g daily dose gets you to the same saturation point within about three to four weeks, with no digestive discomfort along the way. The International Society of Sports Nutrition's position stand backs both approaches as safe and effective; it's genuinely a matter of patience versus convenience, not efficacy.
Skip the loading phase unless you have a specific reason not to. Most people buying creatine aren't peaking for a meet in ten days — they're trying to add a bit more to their bench press over the next six months, and there's no advantage to rushing the saturation curve for that.
Who actually benefits — and it's a wider group than "the gym crowd"
Resistance trainers and sprint-based athletes see the clearest gains, but the evidence base has widened noticeably over the past few years. Older adults doing resistance training show better preservation of muscle mass and strength when creatine is combined with training, compared with training alone — relevant given how much NHS guidance on healthy ageing now emphasises strength work, not just walking, for people over 65. Vegetarians and vegans, who get little to no dietary creatine from food, tend to start with lower baseline muscle stores and often see a larger relative jump from supplementing than meat-eaters do, simply because they have more room to fill. There's a smaller, newer body of research looking at creatine and cognitive fatigue — particularly under sleep deprivation — but this is where the marketing has run well ahead of the science. A handful of studies suggest a modest effect on mental fatigue during sleep loss; that is a long way from the claims some supplement brands now put on packaging about "brain performance" for people sleeping normally. If you're getting a solid seven hours a night, don't buy creatine expecting a noticeable cognitive edge — you'll likely notice nothing beyond the effect on your training. Save the money for the gym membership instead, where the evidence is actually strong.
Where UK shoppers overspend
Creatine monohydrate is creatine monohydrate.
That's the part worth being blunt about — the price differences on UK shelves have almost nothing to do with quality. Myprotein's Creatine Monohydrate (250g, roughly £9.99) and Bulk's own Creatine Monohydrate Powder (1kg, around £19.99) use the same compound, at the same purity standard, as Applied Nutrition's or Optimum Nutrition's versions costing two to three times more per gram. "Micronised" creatine — ground finer so it dissolves more easily in water — is a genuine texture difference, not a performance one; if you don't mind a bit of grit at the bottom of your shaker, standard monohydrate works identically.
Skip anything marketed as creatine hydrochloride, buffered creatine ("Kre-Alkalyn"), or liquid creatine at a premium price — none of these forms have shown a performance advantage over plain monohydrate in head-to-head trials, despite routinely costing more. Creatine monohydrate remains the only form with genuinely deep research support, and the Creapure-branded monohydrate used by several UK supplement companies (including some Bulk and Myprotein lines) is manufactured to a purity standard worth checking the label for if you want reassurance beyond "trust the brand."
The side effects worth actually knowing about
Creatine monohydrate has one of the cleanest safety profiles of any widely sold sports supplement, with the European Food Safety Authority accepting a claim that 3g a day supports muscle performance in high-intensity, intermittent exercise. That's not nothing — EFSA doesn't approve health claims casually. But "generally safe" isn't the same as "safe for everyone, no questions asked."
Here's the nuance that gets skipped in most supplement-shop chat: people with existing kidney disease, or anyone with a family history of kidney problems, should talk to a GP before starting creatine, because the compound is processed through the kidneys and the long-term data in that specific population is thinner than the data for healthy adults. For the general population — which is most people reading a supplement label in a UK shop — decades of trials, including ones running several years, haven't turned up kidney damage from standard doses. The caution is real, but it applies to a specific group, not to creatine as a category.
Creatine and women — the gap the research hasn't closed
Most of the foundational creatine trials were run on male athletes, and it shows: dosing guidance, loading protocols and even the "expect some water retention" advice are largely extrapolated from male physiology rather than tested directly on women across a menstrual cycle. Emerging research — some of it out of Australian and Canadian sports science departments in the past two to three years — suggests creatine needs and response may shift across the cycle, and that women may be more likely to be under-dosed by generic "3–5g" advice built around male body composition. This is genuinely unsettled territory, not a marketing angle some brands have started using it as.
None of that changes the basic advice. A standard 3–5g daily dose of plain creatine monohydrate, taken consistently, remains the sensible starting point for almost anyone training with weights two or three times a week — man or woman, 25 or 65. Buy the cheapest pure monohydrate on the shelf, take it daily rather than only on training days, and give it a month before deciding whether you've noticed anything. Anything sold as a shortcut to that process is selling you packaging, not chemistry.