International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine
Reviews 500+ studies and concludes creatine monohydrate is the most effective ergogenic nutritional supplement for high-intensity exercise and lean body mass, with an excellent safety profile across populations.
Formulate methodology review
As a position stand synthesizing over 500 primary studies, its grade reflects the aggregate evidence it summarizes — and the creatine literature is unusually deep. Creatine monohydrate has been replicated across decades, populations, and research groups. The main caveat is that ISSN member authors often have industry relationships with sports nutrition companies, and conclusions about safety in vulnerable populations (adolescents, renal disease, pregnancy) rely on extrapolation rather than direct trials.
A Cochrane systematic review conducted by independent methodologists would add a final confirmatory tier. For most purposes, though, the creatine evidence base is already among the most mature in any supplement category.
Opinion based on the published paper's methodology. Reviewed 2026-04-21. See our methodology rubric for scoring conventions. Not medical advice.
What these flags mean for you
Each flag on this study comes with a plain-English breakdown of why it matters and how it should change the confidence you place in the result.
Independent research groups have reproduced this finding in separate populations.
Replication is the strongest signal in science. A replicated finding is orders of magnitude more likely to be real than a novel one.
Treat the central claim as reliable. Edge cases (different populations, doses, formulations) may still vary.
The trial enrolled enough participants to detect realistic effect sizes with high statistical power.
Large samples shrink the role of chance. A positive finding in thousands of people is much less likely to be a fluke than the same finding in dozens.
Gives you more confidence the reported effect size is close to the true effect — but still doesn't prove the study is well-designed in other ways.
How to read a study like this
The same questions worth asking about any research paper, not just this one. Worth a minute even if you trust the grade.
Supplement effects often depend on baseline status. Vitamin D helps people who are deficient; iron helps people who are anemic. A result in people unlike you may not apply to you.
A study that shows a blood marker moved isn't the same as a study that shows people felt or functioned better. Ask what the outcome means in practice.
'Statistically significant' only means the effect is unlikely to be zero. It doesn't tell you the effect is large enough to notice. Look for effect sizes, not just p-values.
Industry-funded trials are several times more likely to report positive results than independent ones. It's not usually fraud — it's subtle design and reporting choices. Weight accordingly.
Single positive trials are hypotheses. Replication by independent groups is what turns a hypothesis into reliable evidence. If the only positive trial is the one you're reading, wait.
Supplement marketing routinely cites trials that used 5–10× the dose in the product. If the effective dose was 2 g/day and the capsule has 200 mg, expect roughly no effect.
Not medical advice. This breakdown is for educational purposes. Nothing here constitutes an allegation of fraud or misconduct by any researcher or sponsor. Reasonable scientists can grade the same paper differently; we show our rubric and link every claim to the original study.