Creatine monohydrate improves strength and short-burst power output when paired with resistance training, according to the International Society of Sports Nutrition's 2017 position stand — with effects that are consistent but modest, and larger in men than in women. It is among the most-studied supplements in sports science, and the research base has only grown since.
The compound is not exotic. Creatine is made from amino acids and stored mostly in skeletal muscle, where it helps regenerate the fuel used during short, hard efforts — a sprint, a heavy set, a jump. The body makes about a gram a day on its own and gets more from red meat and seafood, but supplementation raises muscle stores well beyond what diet alone provides, according to the ISSN position stand, authored by a panel led by Hector L. Lopez of Supplement Safety Solutions and published in the Journal of the International Society of Sports Nutrition.
How much stronger does creatine actually make you?
A 2025 systematic review and meta-analysis in the journal Nutrients, led by Frédéric Dutheil and covering 69 randomized controlled trials with 1,937 participants, found creatine combined with resistance training produced small but statistically significant strength gains — a weighted mean difference of 1.43 kilograms in bench and chest press strength, along with gains in squat strength. Vertical jump improved by 1.48 centimeters and Wingate test peak power rose by 47.81 watts on average across the pooled trials.
Not every measure moved. The same analysis found no significant improvement in handgrip strength or leg press, a reminder that creatine's benefit shows up most reliably in compound, explosive, or repeated-effort movements rather than every strength metric researchers track. The ISSN position stand puts the broader range at 10 to 20 percent for strength and power activities, depending on how much a person's muscle phosphocreatine stores rise with supplementation — a figure that varies by individual.
Does creatine work the same for everyone?
No. The Nutrients meta-analysis found benefits were “most consistent in younger adults and males,” while older adults and women showed smaller or non-significant changes across several of the outcomes measured. The ISSN position stand likewise notes that women may see smaller strength and muscle-mass gains than men on the same protocol, even as both groups are represented in the supporting research spanning adolescents through older adults.
That gap doesn't mean creatine does nothing for women or older lifters — both meta-analyses include those populations among study participants with measurable, if smaller, effects. It means a reader comparing their own results to headline numbers from mixed-sex trials should expect the average to overstate what any single demographic experiences.
How should someone actually take it?
The ISSN position stand outlines two established protocols. A loading phase uses roughly 5 grams of creatine monohydrate, taken four times daily, for five to seven days, followed by a maintenance dose of 3 to 5 grams daily — with larger athletes potentially needing more, up to roughly 5 to 10 grams. Skipping the loading phase and taking 3 grams daily for 28 days produces the same eventual muscle saturation more gradually, according to the same position stand.
| Protocol | Dose | Duration |
|---|---|---|
| Loading phase | ~5 g, four times daily | 5-7 days |
| Maintenance (after loading) | 3-5 g daily | Ongoing |
| No-loading approach | 3 g daily | ~28 days to saturation |
Is the kidney damage concern legitimate?
The most persistent worry about creatine — that it damages the kidneys — is not supported by the evidence supplied here. Mayo Clinic states that “studies in healthy people who take creatine haven't found that creatine harms kidney function when taken at recommended doses,” and rates the supplement as generally safe for use up to five years. The ISSN position stand goes further, citing research on doses as high as 30 grams daily sustained for five years without clinically significant adverse effects in healthy populations or in patient groups ranging from infants to older adults, with no evidence of renal dysfunction or muscle cramping tied to supplementation.
Mayo Clinic's one clear caution is for people who already have kidney disease, who should talk to a clinician before starting creatine. The most commonly documented side effect in the general population is water-related weight gain, not organ harm. Mayo Clinic also notes that combining creatine with caffeine may blunt its effectiveness, an interaction worth knowing if a training routine already includes a pre-workout stimulant.
What does this mean for someone training right now?
For lifters and athletes doing repeated high-intensity efforts — heavy sets, sprints, jump work — the pooled trial evidence supports a real, if modest, strength and power benefit from creatine monohydrate at standard doses, most reliably in younger male trainees and in compound or explosive movements. The safety data supplied here, spanning multi-year studies, does not support the kidney-damage concern that still circulates informally. None of this is a substitute for individualized guidance: anyone with existing kidney disease, other medical conditions, or questions about how a supplement interacts with their own training and health history should talk to a physician or registered dietitian before starting. This article is informational and not medical or training advice.
For a related training perspective, read What the Research Says About Creatine and Muscle Growth.
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