Creatine: The Best-Tested Supplement You Can Buy

Most of this site is spent telling you that a popular supplement has less evidence than its marketing. Creatine is the opposite case, a supplement with more evidence than its reputation, still explained away as a bodybuilding powder. On a longevity site it earns its place through an unglamorous fact: after 60, the muscle you keep is one of the better predictors of how the next decades go.

Why creatine is on a longevity site

Sarcopenia, the age-related loss of muscle and strength, tracks with falls, fractures, metabolic disease and mortality. The interventions that slow it are resistance training first, protein second, and creatine as the only supplement with consistent trial support for amplifying the first one. Creatine does not build muscle sitting in the jar; it lets you do slightly more work per session, and the sessions compound.

The International Society of Sports Nutrition’s position stand, the field’s consensus document, summarises several hundred trials: creatine monohydrate improves high-intensity exercise capacity and lean mass gains during training, and long-term supplementation at studied doses is safe in healthy populations, including older adults. There is no other supplement on this site where I can cite a sentence that strong.

What is actually proven

Strength and lean mass, robustly: typical trial results show meaningfully larger strength gains over a training block versus placebo, with a kilogram or so of extra lean mass early on, part of it water drawn into muscle, which is not a trick but part of how the mechanism works. Performance effects concentrate in short, repeated, high-intensity efforts; endurance benefits are modest to absent.

Mechanistically it is simple: creatine expands the phosphocreatine pool your cells use to regenerate ATP in the first seconds of hard effort. More buffer, one or two more reps, slightly faster recovery between sets. Everything downstream is ordinary training adaptation, just accumulated a little faster.

The brain claims, honestly sized

The brain runs on the same ATP economics as muscle, and holds its own creatine pool, which is the rationale for the cognitive claims. The human data: a systematic review of six RCTs (281 people) found benefits mainly in short-term memory and reasoning, with the clearest effects in vegetarians, whose baseline stores run lower, and a 2024 meta-analysis of sixteen trials found small-to-moderate improvements in memory and processing speed, not in every cognitive domain.

Two honest qualifiers. The effects are smallest in young, omnivorous, well-rested adults, the group buying most of the tubs. And the most interesting condition, cognition under sleep deprivation, where creatine appears to blunt the decline, is exactly the state this site would rather you fixed at the source. I take creatine and I still file the brain benefits as a bonus, not the purchase justification.

Dose, form, and the loading question

The protocol fits in one line: 3 to 5 g of creatine monohydrate, once a day, any time, with anything, forever. Timing does not meaningfully matter; consistency does, because the effect comes from saturated muscle stores, which take three to four weeks to fill at 3 to 5 g daily.

Loading, 20 g daily for a week, fills the stores in days instead of weeks and is otherwise unnecessary; it mainly buys gut discomfort sooner. And the form question has a rare clean answer: monohydrate is the form used in essentially all the positive trials. Hydrochloride, buffered, ethyl ester and the rest cost more and have never beaten it. If you want a quality marker, Creapure denotes a well-tested German source; unflavoured powder avoids the sweetener ballast.

At Polish and UK retail prices, 5 g daily of plain monohydrate costs roughly £3 to 5 a month. Per unit of demonstrated effect, nothing else in the supplement aisle comes close.

Cost per proven effect

A comparison worth making explicit, across the supplements covered on this site:

Creatine sits alone in the top-left corner: the cheapest per month of the four, with an evidence base an order of magnitude deeper than the rest combined. That asymmetry is the actual argument of this article. Most supplement decisions are bets on thin data; this one is not, and the price of the bet is a coffee a month.

The myths that will not die

Kidneys. Creatine raises creatinine, the breakdown product used as a kidney-function marker, which makes lab results look worse without the kidneys being worse. Trials in healthy people, including multi-year use, show no kidney damage; the position stand addresses this directly. With actual kidney disease, supplement decisions belong to your nephrologist.

Hair loss. The entire scare traces to a single 2009 study in rugby players showing a rise in DHT, without measuring hair at all. No trial since has shown creatine causing hair loss. One unreplicated hormonal blip versus hundreds of trials is not a controversy; it is a rumour with a citation.

Water weight. True, intramuscular, and part of the mechanism. The scale goes up about a kilogram; your waist does not.

It is a steroid. It is a compound your liver already synthesises daily and your steak dinner contains. The supplement just tops up the pool.

What we do not know

Whether creatine measurably changes long-term cognitive or muscle outcomes over decades, nobody has run that trial and nobody will. The cognitive effects in well-rested young omnivores are small enough that some trials find nothing. Historical trial populations skewed male, and while newer work in women and older adults is accumulating and looks consistent, the depth is thinner. And responders vary: people with high baseline stores, heavy meat eaters, may feel close to nothing.

Where to start

If you resistance train, or are past 50 and intend to keep your muscle: 5 g of monohydrate in whatever you drink in the morning, and judge it after eight weeks of training by your log, not the mirror at day three. If you are vegetarian, the case is stronger on both the muscle and brain side. If you do not train at all, creatine is the wrong first purchase; the training is the intervention, and even the boring sleep basics will move your health more than any powder poured onto a sedentary week. If evening coffee is what wrecks your sleep, start with caffeine and sleep.