Creatine is unusual in this category. It is cheap, it has been studied in humans for more than thirty years, the effect on muscle is not seriously disputed, and the marketing is quieter than the evidence would justify. Most longevity supplements have the opposite profile.
It is also the supplement most likely to make one of your lab results look wrong.
The Verdict
Why creatine matters for aging, not just training
Creatine works by recycling ATP. Cells store it as phosphocreatine and use it to regenerate energy during short, intense demand. Muscle holds the largest reserve, and the brain holds a smaller one.
The relevance to healthspan runs through sarcopenia, the progressive loss of muscle mass and strength that begins in the fourth decade and accelerates later. Muscle mass predicts fall risk, metabolic health, and independence in older age. Anything that helps preserve it is doing longevity work, whatever the label on the tub says.
The important qualifier appears in every trial: creatine amplifies resistance training rather than substituting for it. In older adults, creatine plus training beats training alone. Creatine without training produces intracellular water retention and very little else.
What the evidence supports, by claim
| Claim | Strength of evidence | What the trials show | The qualifier |
|---|---|---|---|
| Strength and power output | Strong | Consistent across decades of trials, in trained and untrained adults, in both sexes. | The effect requires resistance training. Creatine without training produces water weight, not strength. |
| Lean mass retention with age | Moderate to strong | Trials in adults over 60 combining creatine with resistance training show greater lean mass gains than training alone. | The training is the active ingredient. Creatine amplifies it. |
| Memory and cognitive performance | Moderate | Meta-analyses report small improvements in short-term memory and reasoning, largest in older adults and vegetarians. | Effect sizes are modest and the trials are short. |
| Performance under sleep deprivation | Moderate | Cognitive decrements from sleep loss are partly offset in several small trials. | Not a substitute for sleep, and studied over days rather than months. |
| Bone density | Weak | Mixed results. Some trials with resistance training show benefit at the hip; others show none. | The evidence does not currently support buying creatine for bone density. |
| Depression and mood | Early | Adjunctive trials suggest a signal, mostly in women. | Preliminary. Not an established use. |
Which form to buy
This section is short because the answer is settled.
| Form | Human evidence behind it | Relative cost | Verdict |
|---|---|---|---|
| Creatine monohydrate | Effectively all of it | $ | The reference form. Everything below is compared against it and none has beaten it. |
| Micronised monohydrate | Same as monohydrate | $ | Smaller particles, better mixing. No absorption advantage that changes outcomes. |
| Creatine HCl | Minimal | $$$ | Marketed on solubility. No trial shows superior muscle creatine loading. |
| Buffered creatine (Kre-Alkalyn) | Tested and not superior | $$$ | A head-to-head trial found it no better than monohydrate, and worse at the low dose used. |
| Creatine ethyl ester | Tested and inferior | $$$ | Degrades to creatinine more readily. Raised muscle creatine less than monohydrate. |
| Liquid or "serum" creatine | Poor | $$$ | Creatine is unstable in solution and converts to creatinine over time. |
Creatine monohydrate is the form in nearly every published trial and the cheapest option on the shelf. Look for a third-party purity certification, since creatine is a bulk commodity ingredient and contamination is the realistic quality risk rather than potency.
The stacked formulas, and what the added ingredients are doing
The table above settles which creatine to buy. It does not settle the question the shelf now poses, because the premium end of the category has moved away from plain tubs. A growing number of products pair creatine monohydrate with other compounds marketed for aging, most commonly HMB and urolithin A, and charge several times the price per serving for the combination.
That price gap is defensible only if the additions carry evidence comparable to creatine's own. They do not. Each sits on its own footing, and the two most common additions sit on quite different ones.
| Added ingredient | What it is | Strength of evidence | What the trials actually showed | The catch |
|---|---|---|---|---|
| HMB (β-hydroxy-β-methylbutyrate) | A metabolite of the amino acid leucine | Moderate in adults over 50 | A 2025 meta-analysis of 21 trials in 1,935 adults over 50 found lean mass higher by 0.28 kg, gait speed by 0.06 m/s, and five-time chair-stand time lower by 0.73 seconds. | The authors flag publication bias, and rate the handgrip and six-minute-walk results as very low quality evidence. Benefits appeared at 3 g daily sustained beyond 12 weeks, so an under-dosed blend is unlikely to reproduce them. |
| Urolithin A | A compound produced by gut bacteria from ellagitannins in pomegranate and walnuts | Early, and weaker than the marketing implies | A four-month randomised trial in 66 adults aged 65 to 90 taking 1,000 mg daily missed both of its co-primary endpoints: neither six-minute walk distance nor maximal ATP production in hand muscle separated from placebo. | The result quoted in marketing is muscle endurance, a secondary endpoint, which reached significance at two months and no longer did so against placebo at four. A second trial in middle-aged adults reported strength gains. Both were run with the ingredient manufacturer involved. |
| Creatine plus HMB together | The two combined, the usual pitch for a blend | Preliminary | The additive-effect finding most often cited is a small trial from 2001. More recent crossover work in physically active older adults points the same way. | The combination has not been tested at anything like the scale creatine alone has. Plausible synergy is not a demonstrated one. |
How to price a blend against plain monohydrate
Creatine monohydrate is a bulk commodity ingredient and costs cents per serving. A blend is not, so the comparison worth running before buying is arithmetic rather than a judgement about ingredients. Three checks do it.
| Check | What to look for | What a weak answer looks like |
|---|---|---|
| Is each active dosed at the amount that was studied? | A label stating the milligrams of every active, at or near the trial amounts: roughly 3 to 5 g creatine, 3 g HMB, 500 to 1,000 mg urolithin A | A "proprietary blend" giving one combined weight, which can hold a studied dose of creatine and a sprinkle of everything else |
| What does the same basket cost bought separately? | The blend's cost per serving set against monohydrate plus each active purchased on its own, at the same doses | A per-serving price compared only against other blends, which anchors the whole comparison at the premium end |
| Which endpoint does the cited trial support? | The claim on the page matching the endpoint the trial pre-registered as primary | A real citation attached to a claim the paper reports as a secondary or interim finding |
Run those three and most blends resolve into a straightforward question: you are paying a multiple for one ingredient with decades of trials behind it, one with a modest effect in older adults, and one whose largest trial missed its primary endpoint. Whether that is worth it is a personal call about how much weight to put on early evidence. It is not the settled buy that monohydrate on its own is, and anyone with kidney disease or on prescription medication should take a multi-ingredient product to a clinician before starting it, since there is more in the tub to interact with.
Where to read the trials yourself
- Spillane et al. 2009, JISSN: creatine ethyl ester tested head-to-head against monohydrate and found inferior.
- Jagim et al. 2012, JISSN: buffered creatine tested against monohydrate and found no better.
- ISSN position stand on creatine: the consolidated safety and efficacy review.
- van der Merwe et al. 2009, Clin J Sport Med: the 20-player rugby study behind the hair-loss claim. Note that hair was never measured.
- Liu et al. 2022, JAMA Network Open: the four-month urolithin A trial in adults aged 65 to 90. Read the endpoint section, not the abstract's closing line.
- Singh et al. 2022, Cell Reports Medicine: the urolithin A trial in middle-aged adults reporting strength gains.
- Andreux et al. 2019, Nature Metabolism: the first-in-human urolithin A safety and mitochondrial signature study.
- HMB meta-analysis in adults over 50: 21 trials, 1,935 participants, with the publication-bias and evidence-quality caveats stated by the authors.
How it is taken in the research
- Maintenance in most trials is 3 to 5 g per day, taken at any time of day. Timing relative to training has not shown a meaningful difference in outcomes.
- Loading is optional. Around 20 g daily split into four servings for five to seven days saturates stores quickly; 3 to 5 g daily reaches the same point in three to four weeks.
- Consistency matters more than timing, because the effect depends on keeping muscle stores saturated rather than on any acute dose.
- Larger people and those with more muscle mass sit at the upper end of that range in trials, since the reservoir being filled is bigger.
- Gastrointestinal complaints cluster in the loading phase and with large single servings taken on an empty stomach.
These are the amounts studied, not a recommendation for you. Anyone with kidney disease, on nephrotoxic medication, or pregnant should take this to a clinician first.
The brain dose is not the muscle dose
Muscle and brain do not respond to the same amount. Muscle takes up creatine readily and saturates at 3 to 5 g a day within a few weeks. The brain is behind a transporter-limited barrier, so brain creatine rises more slowly and less completely on the same intake, which is why cognition trials frequently run higher doses or longer durations than the muscle literature does.
- The best-known cognitive trial used 5 g a day for six weeks in young adult vegetarians and reported improvements in working memory and abstract reasoning (Rae et al., 2003). That is the same dose used for muscle, which is the reason the finding attracted attention.
- Replication has been uneven. Later randomised work has not consistently reproduced the effect in mixed-diet populations, and a more recent study found no sign that vegetarians benefited more than omnivores. Treat cognition as a plausible secondary effect rather than a reason to buy the powder.
- The clearest signals appear under energy stress. Trials during sleep deprivation and mental fatigue show larger effects than trials in rested, well-fed participants, which fits the mechanism: creatine buffers cellular energy, so it helps most when energy supply is the limiting factor.
- Higher doses are not a free upgrade. Gastrointestinal complaints scale with dose, and the long safety record sits at 3 to 5 g a day rather than at the larger amounts some cognitive protocols use. If you are taking creatine for muscle anyway, the brain exposure comes along with it.
Two groups are worth separating. Vegetarians and vegans start with lower dietary creatine intake, since meat and fish are the only meaningful food sources, so the same dose represents a larger relative increase for them. Older adults are the group with the most to gain from the muscle effect, and the trials in them combine creatine with resistance training rather than testing it alone. Dosing questions specific to women are covered on creatine for women.
What to check before and after starting
| Marker | Why it is relevant | When to check |
|---|---|---|
| Creatinine and eGFR | Will rise slightly from the supplement itself. Establish where you sit before starting so a later reading is interpretable. | Baseline, then annually |
| Cystatin C | An alternative filtration marker unaffected by creatine or by muscle mass. Resolves an ambiguous creatinine result. | If creatinine looks elevated |
| Lean mass (DEXA or bioimpedance) | The outcome creatine plus training is meant to change. Body weight alone conflates water, fat and muscle. | Baseline, then at 6 to 12 months |
| Strength benchmarks | The most sensitive readout available to you, and free. | Continuously |
A baseline creatinine recorded before starting is what converts a future ambiguous result into an interpretable one, and it is the step most often skipped. It also costs nothing if you are already running an annual panel through a testing platform.
How it compares to the rest of the shelf
Ranked by the quality of human evidence per dollar, creatine sits at the top of the longevity supplement market, and the products marketed hardest sit near the bottom. NAD+ precursors cost several times more per month and have not shown a consistent functional benefit. Senolytics rest largely on mouse data. Creatine has decades of trials, a mechanism confirmed by muscle biopsy, and a readout you can observe without buying anything.
The caution worth stating is that the effect is not dramatic and it is conditional on training. Creatine will not change your trajectory on its own. It makes the training you are already doing produce somewhat more, and over a decade of protecting muscle mass that is where its case rests.
Frequently Asked Questions
Does creatine help with anything besides muscle?
The best-supported non-muscle effect is cognitive. Meta-analyses of randomised trials report small improvements in short-term memory and reasoning, with the largest effects in older adults, vegetarians, and people who are sleep-deprived. The mechanism is plausible because the brain uses the same phosphocreatine energy buffer as muscle. The effects are real but modest, and smaller than the effect on strength.
Is creatine safe for your kidneys?
In people with normal kidney function, controlled trials lasting weeks to around two years have not shown kidney damage, and longer follow-up out to about five years comes from observational and case-series data rather than controlled trials. The persistent concern comes from a laboratory artifact rather than a clinical finding: creatine supplementation raises serum creatinine, the marker used to estimate kidney filtration rate, without any change in actual filtration. Anyone with existing kidney disease should have this conversation with their nephrologist rather than resolving it from general population data.
Do you need to load creatine?
No. Loading with roughly 20 g per day split across four servings for five to seven days saturates muscle stores in about a week. Taking the standard maintenance amount of 3 to 5 g daily reaches the same saturation in three to four weeks. Both endpoints are equivalent. Loading only shortens the wait, and it is the phase most associated with gastrointestinal complaints.
Which form of creatine is best?
Creatine monohydrate. It is the form used in the overwhelming majority of published trials, it is the cheapest, and no alternative form has beaten it in a head-to-head test. Buffered creatine and creatine ethyl ester have both been directly compared with monohydrate and neither raised muscle creatine more; ethyl ester performed worse. Paying more for an alternative form buys marketing.
Does creatine cause hair loss?
The concern traces to a single 2009 study of 20 rugby players that found an increase in dihydrotestosterone after three weeks of creatine, with no hair loss measured. No study since has replicated the hormonal finding, and no trial has measured hair loss as an outcome. This is an unresolved question resting on one small study rather than an established effect.
Are creatine blends with HMB and urolithin A worth the extra cost?
They cost several times plain monohydrate, and the added ingredients do not carry comparable evidence. HMB has a moderate case in adults over 50: a meta-analysis of 21 trials in 1,935 people found lean mass higher by 0.28 kg and gait speed by 0.06 m/s, at 3 g daily sustained beyond 12 weeks, with the authors flagging publication bias. Urolithin A is earlier and weaker than its marketing suggests, because the four-month trial in adults aged 65 to 90 missed both of its co-primary endpoints. Before paying the premium, check that each active is dosed at the studied amount rather than hidden in a proprietary blend, and price the same basket bought separately.
Why does urolithin A appear in longevity supplements if its trial failed?
Because the trial produced a positive secondary result and a clean safety profile, and both are real. The four-month study in 66 adults aged 65 to 90 pre-registered two primary endpoints, six-minute walk distance and maximal ATP production in hand muscle, and neither separated from placebo. Muscle endurance, a secondary endpoint, was significant at two months but not against placebo at four. That is the finding quoted on product pages. The mechanism, clearance of damaged mitochondria, is biologically plausible and under active study, so the fair description is an early compound with an unproven functional effect rather than a discredited one.
Who responds most to creatine?
People with low baseline muscle creatine stores. Vegetarians and vegans get almost no dietary creatine, since it comes primarily from meat and fish, so they start lower and typically show larger increases in muscle creatine and larger performance responses. Regular meat eaters sit closer to saturation already, and a subset of people are described in the literature as non-responders whose stores are near maximal without supplementation.