Creatine is stored in muscle tissue as phosphocreatine, which replenishes ATP (the cell’s primary energy currency) during high-intensity exercise. The proposed ergogenic mechanism is that greater phosphocreatine availability sustains ATP resynthesis through short-burst, anaerobic effort such as sprinting, weightlifting, and explosive sports. That mechanism is the rationale for supplementing; it is not itself an outcome, and none of the reviews cited here measured power output.
A 2025 systematic review and meta-analysis pooled 20 studies and 1,093 older adults (69% female, aged 55 and over), each comparing creatine plus exercise training against placebo plus the same training. One-repetition maximum was higher in the creatine groups by a mean difference of 2.122 kg (Z = 3.255, P = 0.001) with no detectable heterogeneity between studies (I² = 0%, P = 0.876). By exercise, the difference was significant for the leg press (P = 0.018) and the lat pull-down (P = 0.022) and not significant for the arm curl, bench press, or chest press. The same analysis found a 0.548 percentage-point reduction in body fat (P = 0.026) and no effect on total-body bone mineral density (P = 0.557), which the authors say needs further study.
What this page does not claim: none of the sources cited here measured peak power output, sprint or repeated-sprint performance, recovery between training sessions, markers of exercise-induced muscle damage, total training volume, or strength in younger trained populations. This page therefore carries no claim about those outcomes, and none about a dose-response relationship, and will carry none until evidence that measured them is curated.
The brain relies heavily on ATP for neurotransmission and cellular maintenance. A 2018 systematic review searched for double-blind randomized trials of oral creatine in healthy individuals over 12 years old and found six, covering 281 participants. Its summary finding is that short-term memory and intelligence/reasoning may be improved by creatine, while results for long-term memory, spatial memory, memory scanning, attention, executive function, response inhibition, word fluency, reaction time, and mental fatigue were conflicting. Short-term memory was tested in four of the six trials: two reported a benefit, one found it only in vegetarians and not in meat-eaters, and one found no effect in a sample of young adults only. Reasoning or mathematical processing was assessed in three trials, two of which reported significant improvement. Cognitive task performance stayed unchanged in young individuals throughout.
The review’s authors go on to raise the possibility that creatine helps “diseased, aged or stressed individuals whereas for younger, unstressed individuals there is no such a benefit”. That is a discussion-level hypothesis drawn from the pattern of results and from trials outside the review, including a sleep-deprivation study that was not one of the six included; no included trial tested cognition under a defined stressor. This page claims short-term memory and reasoning in healthy adults, and claims no effect specific to sleep deprivation, metabolic stress, or low dietary creatine intake. The evidence itself is limited: one included trial was rated at high overall risk of bias, four were unclear, and the review reports that a quantitative meta-analysis was not feasible because the trials differed too much in participant age and sex, supplementation protocol, and the cognitive tasks used.
A growing body of 2024–2025 research positions creatine as a tool for healthy aging beyond athletic populations, and the meta-analysis summarized above is part of it. A 2025 narrative review in the Journal of the International Society of Sports Nutrition concluded that creatine monohydrate, primarily when combined with exercise training, is safe for older adults and has beneficial effects on measures of lean body mass, regional muscle size, muscle strength, bone area and thickness, functional ability, glucose kinetics, cognition and memory, with potential application in age-related sarcopenia, osteoporosis, frailty, and metabolic and neuromuscular disorders. That is a narrative review restating other people’s trials and meta-analyses rather than a source of measurement in its own right, so no claim on this page cites it.
Cognition-specific evidence in older adults is emerging. A 2025 systematic review (6 studies, 1,542 participants) found that 83% of studies reported a positive relationship between creatine supplementation and cognition in older adults, particularly for memory and attention. Evidence quality was mixed, and the authors called for more rigorous clinical trials. A 2025 Alzheimer’s pilot trial (CABA trial, 19 participants, 8 weeks at 20 g/day) found an 11% increase in brain total creatine and significant improvements on global and fluid cognitive composites, feasibility results that warrant a full-scale RCT.
A separate 2025 finding noted that creatine synthesis and dietary intake decline with age and may interfere with DNA methylation patterns associated with biological aging and mortality risk, suggesting a potential longevity mechanism beyond muscle and brain energy metabolism.
A standard dose is 3–5 g/day of creatine monohydrate taken daily. A loading phase (20 g/day split across 4 doses for 5–7 days) saturates muscle stores faster, but the same endpoint is reached with gradual supplementation. Monohydrate is the most researched form; alternative forms (HCl, ethyl ester) offer no documented advantage at equivalent doses.
Creatine monohydrate is widely considered safe for healthy adults. Common concerns about kidney damage or dehydration have not been substantiated in controlled research. Mild water retention in muscle tissue is expected and reflects proper uptake rather than a side effect.