Supplements · Metabolic & Cardiometabolic
creatine is safe for healthy adults
In plain terms: Is creatine safe to take long-term?
Leans support Supplements 💰 Industry COI noted
Part of: 🧪 creatine
RefutedContestedStrong support
consensus score 0.53
Yes — it has one of the strongest safety records of any supplement, with no harm to kidney, liver, or heart markers in healthy adults across trials lasting years. Claims that literally everyone should take it, including pregnant or clinical populations, go further than the evidence.
📅 Last reviewed: 2026-07-14 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
MechanismIn-vitroAnimalObservationalRCTMeta-analysis
How the studies fall
4 support 0 contradict 0 tested null 2 mixed · 6 sources, 4 independent groups
What the evidence shows
Creatine monohydrate has one of the best safety records of any supplement — no adverse effects on kidney, liver, or cardiovascular markers in healthy adults across trials up to years long. (Candow extends this to 'literally everyone incl. clinical/pregnant populations'; that broader claim outruns the healthy-adult evidence and is flagged in his scorecard.)
The evidence (13)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Al-Humadi S et al 2026 · Cureus | observational | supports | low | Narrative review (Cureus, no primary data): 'Overall, these studies suggest creatine is safe with minimal effects on renal function in healthy individuals' and 'The most common side effect is weight gain, and there do not appear to be any adverse effects on renal function in healthy athletes.' Durations ARE given in the full text - Kreider's college footballers took creatine for 12-21 months, and 'a study on creatine supplementation in adult and pediatric patients with neurodegenerative conditions have shown that it is well tolerated with long-term use (up to 30 g/day for five years).' The review qualifies its verdict outside this claim's scope: 'it has been recommended to avoid supplementation in those with poor kidney function.' Secondhand throughout; adds no independent data. |
| Jager 2011 · Amino Acids | observational | supports | low | Analysis: creatine monohydrate has an established safety/regulatory record; novel forms less studied. |
| Longobardi, Gualano, Seguro, Roschel 2023 · Nutrients | observational | supports | low | PARTIAL-SCOPE vote, which the old extract did not say: this review examines the KIDNEY axis only, so it speaks to one of the three organ systems the claim names (kidney, liver, cardiovascular). Within that axis it supports the claim explicitly - 'Based on studies assessing kidney function using reliable methods, creatine supplements have been shown to be safe for human consumption' and 'Altogether, these findings suggest that creatine monohydrate within recommended doses seems to be safe, even when administered in clinical populations' - across ~30 controlled trials in healthy adults, athletes, older adults and clinical populations, several using 51Cr-EDTA measured GFR. Conditions the authors attach: rational doses up to 20 g/day; 'there is a scant amount of long-term studies' beyond 16 weeks; alternative formulations are unproven ('the safety profile of alternative commercialized forms of creatine other than creatine monohydrate cannot be fully stablished'); uncertified low-price products 'with unattested purity and a plethora of contaminants ... should be avoided'; and safety is NOT extended to pre-existing kidney disease. Narrative review with no systematic method, heavily self-citing, and senior author Gualano sits on the Scientific Advisory Board of AlzChem, a creatine manufacturer, and receives creatine donations and honoraria from it - so supports / review-role / quality low all stand as recorded. |
| Antonio, Candow, Forbes, Gualano, Jagim, Kreider, Rawson, Smith-Ryan, VanDusseldorp, Willoughby, Ziegenfuss 2021 · J Int Soc Sports Nutr | observational | supports | low | Narrative review (no search strategy, no risk-of-bias, not systematic) answering 12 creatine questions. Its safety verdict is real but DOSE-CONDITIONED, and the recorded extract dropped that: 'evidence-based research shows that creatine supplementation is relatively well tolerated, especially at recommended dosages (i.e. 3-5 g/day or 0.1 g/kg of body mass/day)', and 'when ingested at recommended dosages, does not result in kidney damage and/or renal dysfunction in healthy individuals'. Loading is described as 20 g/day for 5-7 days, and the cited renal case reports are explicitly confounded by 'inappropriate creatine dosages (e.g., 100 X recommended dose)'. Stance stays supports; quality stays low, and it should - Darren Candow is the second author and conceptualized the paper ('Conceptualization: DGC'), the first author is CEO of the ISSN which takes sponsorship from creatine manufacturers, and six of eleven authors sit on the Scientific Advisory Board of Alzchem (a creatine manufacturer), one as its Chair. Funding is declared 'Not applicable'. |
| de Camargo KMR et al 2026 · study_type: meta-analysis | meta-analysis | mixed | moderate | Meta-analysis of 8 RCTs (healthy individuals, athletes, and clinical populations) found no significant acute or chronic effect of creatine on CRP or IL-6, i.e. no pro-inflammatory adverse signal; duration varied by included trial, not speci |
| Poortmans, Francaux 2000 · Sports Med. 2000 Sep;30(3):155-70 | observational | supports | low | Review: adverse-effect concerns are largely unsupported; creatine well-tolerated in healthy adults. |
| Almeida 2020 · J Sports Med Phys Fitness | RCT | supports | low | Double-blind placebo-controlled trial in ~18 male resistance-training practitioners, creatine monohydrate 0.3 g/kg/day for 7 days vs dextrosol: 'Creatine monohydrate supplementation did not cause adverse events and, as expected, promoted an increase of the performance and body weight', with no modification of red or white cell parameters, lipids, metabolic and urine markers, or hepatic and renal function; the authors conclude 'the creatine monohydrate supplementation is safe for health and no detrimental effects on different organs and physiological systems were observed in our cohort of volunteers.' Quality low: ~18 young trained males, 7 days of exposure, zero effect sizes or p-values reported, so the null has almost no power to exclude the harms it is cited against. |
| Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, Candow DG, Kleiner SM, Almada AL, Lopez HL 2017 · J Int Soc Sports Nutr | observational | supports | low | ISSN position stand (narrative review, no search strategy or pooling; Council for Responsible Nutrition-commissioned, Candow is a co-author). Position statement 3: 'There is no compelling scientific evidence that the short- or long-term use of creatine monohydrate (up to 30 g/day for 5 years) has any detrimental effects on otherwise healthy individuals or among clinical populations who may benefit from creatine supplementation.' Safety section: 'Available short and long-term studies in healthy and diseased populations, from infants to the elderly, at dosages ranging from 0.3 to 0.8 g/kg/day for up to 5 years have consistently shown that creatine supplementation poses no adverse health risks', concluding 'The breadth and repetition of these findings provide compelling evidence that creatine monohydrate is well-tolerated and is safe to consume in healthy untrained and trained individuals regardless of age.' The one harm the paper concedes: 'The only consistently reported side effect from creatine supplementation that has been described in the literature has been weight gain'. Supports the claim, but as a downstream summary of others' trials, not an observation. |
| Gimenez FVM et al 2026 · study_type: meta-analysis | meta-analysis | supports | low | Meta-analysis of 8 RCTs in adults found no statistically or clinically significant effect of creatine supplementation on total cholesterol, LDL-C, HDL-C, or triglycerides (durations per included RCTs, not specified in abstract). |
| Naddafha S, Antonio J, Kreider RB, Stout JR 2026 · J Int Soc Sports Nutr | meta-analysis | supports | moderate | Safety across 7 RCTs in postmenopausal women (12-104 weeks, median 38) — narrative, not pooled: 'No serious adverse events (SAEs) attributable to creatine were reported'; renal indices unchanged (Gualano 2014 urea/creatinine/AST/ALT no differences; Sales 2020 no change in creatinine or eGFR over 2 years; Chilibeck 2023 renal and liver markers no clinically significant differences); no blood-pressure effect. Authors' GRADE high certainty. Qualifier the prior extract omitted: in the 1-year Candow/Chilibeck trial mild GI symptoms were more common with creatine (5 vs 0) and cramping 2 vs 0, and 'considered together, these events reached statistical significance' — all self-limited, none prompting withdrawal. |
| Longobardi I, Solis MY, Roschel H, Gualano B 2025 · Frontiers in Nutrition | observational | supports | low | Short narrative review, whole-paper verdict — the previous extract was truncated mid-word at 'described as gene'. Bottom line: 'When used at recommended doses (5–20 g/day), creatine monohydrate is safe for most populations and has well-documented performance and clinical benefits.' Table 1 grades cancer 'Not supported / II', kidney function 'Not supported / I', dehydration-thermoregulation 'Not supported / I', muscle cramps 'Not supported / II', GI distress 'Unlikely / II'. Largest supporting denominator, reported secondhand: 'Kreider et al. evaluated 685 randomized controlled trials with over 26,000 participants and found no significant differences in the prevalence or frequency of GI issues between creatine and placebo groups (5.5% vs. 4.2%, p = 0.820)'. GI distress is real but dose-shaped, not creatine-shaped — a 59-player randomised trial found 'Cr10 showed a higher incidence of diarrhea than Cr5 (55.6% vs. 28.6%' while 'After 28 days, diarrhea (39%), stomach upset (23.8%), and belching (16.9%) were reported across all groups, including placebo.' WHERE THE REVIEW STOPS, which is the boundary this claim's depends on: 'though caution is advised for those with pre-existing kidney conditions and pregnant women, as evidence is lacking for these populations', and on pregnancy specifically 'the absence of randomized controlled trials in humans remains the most significant barrier' with the instruction 'Until such studies are conducted, creatine supplementation should not be recommended in clinical practice outside of research protocols.' Generalisability limit in the authors' words: 'participants in all studies were predominantly healthy young men'. Manufacturer COI: 'AlzChem provided financial support for the article processing charges (APCs)'; the senior author served on AlzChem's Scientific Advisory Board. |
| de Souza e Silva 2019 · J Renal Nutr | meta-analysis | mixed | low | SR+MA of 6 pooled studies, renal outcomes only. Its premise names liver, quality of life and mortality - 'there are indications that it can overwhelm liver and kidney functions, reduce the quality of life, and increase mortality' - but the only measured outcomes are serum creatinine (SMD = 0.48, 95% CI 0.24-0.73, P = .001) and plasma urea (SMD = 1.10, 95% CI 0.34-1.85, P = .004), both reported as significant increases while the text calls them unchanged. A renal-marker-only slice with an internal prose/number contradiction cannot underwrite a general safety verdict; tempered to mixed. Population never stated as healthy adults in the available text. |
| Gonzalez DE et al 2026 · Sports (Basel) 2026;14(4):137, MDPI | meta-analysis | supports | low | Structured review / study-level re-analysis of an existing 684-RCT database ('No new data were created or analyzed in this study'). Direction supports the claim: 'Out of all included RCTs, 93 (13.6%) recorded at least one participant having reported a side effect following supplementation with creatine, while 591 (86.4%) did not', and organ-system harms were near-absent — 'In this review, only three trials reported renal or urinary side effects', one trial reported a liver/metabolic event, six reported cardiovascular events. But the recorded strength was overstated on three counts. (1) The paper reports statistically significant dose-tertile associations for gastrointestinal (p < 0.001), renal/urinary (p = 0.047) and musculoskeletal (p < 0.001) side-effect reporting; the authors' defence is that the effect sizes are small (phi-c 0.09-0.16) and events sparse, not that no association exists. (2) The design is ecological — 'Accordingly, conclusions should be interpreted within the constraints of an ecological study-level analysis and should not be construed as definitive estimates of individual risk', with each RCT arm 'given equal weight in the analysis regardless of sample size', no risk-of-bias assessment, no registration, and the authors' own warning that 'null results in low-frequency categories should not be seen as conclusive evidence of no risk but rather as due to limited event data'. (3) The corpus pools children, older adults and clinical populations with no healthy-adult-only stratum, and the analysis's own denominator is '1337 participants' (Methods and Discussion), not the '>12,800 participants' figure the prior extract carried over from Kreider et al. 2025. Three authors serve on creatine-manufacturer scientific advisory boards. |
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