A reference work, not a recommendation to use: this profile describes mechanism and evidence and does not replace medical advice. The claims come from marketing and forums and are tested here, not endorsed.

Claims checked

  • More strength and muscle mass with training

    Small benefit

    Muscle & performance · mixed: adults doing resistance training, mostly healthy people, also patient groups · Human, randomised

    Meta-analysis of 63 placebo-controlled RCTs with creatine monohydrate (according to the results section all studies, according to the discussion the vast majority): upper-body strength g 0.54, lower-body strength g 0.55, lean mass g 0.30; after correction for publication bias, strength g 0.36 and 0.35, respectively; certainty low to moderate, larger effects in younger people only exploratory [3]. Monohydrate subgroup of a second meta-analysis: fat-free mass +1.35 kg [4]. Consistently documented, but small to moderate; hence “Small benefit.” Population “mixed” because [4] also includes studies in patients (e.g., knee osteoarthritis, osteopenia, after stroke, HIV infection) and [3] only restricts to adults aged 18 and older. The older meta-analysis without information on the form [5] does not count. The authorized EU claim is not an evidence level [16].

  • Better mental performance in healthy people

    Small benefit

    Cognition & focus · healthy · Human, randomised

    Meta-analysis of RCTs with creatine monohydrate: small memory benefit, mainly in older adults, practically zero in younger ones [12]; largest RCT only borderline [10]; signs of a benefit under sleep deprivation [8]. All three sources used monohydrate. Two authors of the meta-analysis [12] declare ties to creatine manufacturers.

Mechanism of action

Evidence map: Creatine monohydrate

Each line stands for a published finding; line style and color show where it comes from. The filter hides weaker evidence levels. Sources: see references.

Creatine is made mainly in the liver and kidney from arginine and glycine: arginine-glycine amidinotransferase (AGAT) forms guanidinoacetate, which guanidinoacetate N-methyltransferase (GAMT) methylates with S-adenosylmethionine to creatine. About 95% of the body's creatine is in skeletal muscle, roughly two thirds of it as phosphocreatine, which rapidly replenishes ATP via creatine kinase when energy demand is high; each day, about 1–2% of muscle creatine is broken down to creatinine and excreted in the urine [1]. Creatine monohydrate contains 87.9% creatine by mass. A critical review found no documented advantage for any other form and rates monohydrate as the only creatine source with extensive data on bioavailability, efficacy and safety [2]. Both reviews come from author groups with declared ties to creatine manufacturers (consulting, research funding, former patents); the position statement [1] was prepared at the request of, and with support from, the Council for Responsible Nutrition.

For strength and muscle mass during resistance training, one meta-analysis pooled 63 randomized, placebo-controlled studies with 1489 participants. According to the results section (characteristics of the included studies), all studies used creatine monohydrate; the discussion speaks of the “vast majority.” Compared with resistance training with placebo, upper-body strength (Hedges' g 0.54; 95% CI 0.37–0.71), lower-body strength (g 0.55 after excluding one outlier, 0.66 with it) and lean mass (g 0.30; 95% CI 0.18–0.41) increased more, fat mass did not. For both strength measures, tests pointed to publication bias; after correction, g 0.36 and 0.35 remained. In exploratory analyses, the strength effects were somewhat larger in younger adults; in adults aged 60 years and older they were also significant, in the few effect sizes from the 45 to 59 age range they were not. The authors explicitly do not regard this age pattern as confirmed; they rated the certainty of the evidence as low to moderate [3]. A second meta-analysis of controlled studies found 1.35 kg more fat-free mass (95% CI 1.05–1.64) and 0.87 kg more body weight than with placebo in the monohydrate subgroup; several authors declare consulting work, research funding or creatine donations from manufacturers [4]. An older meta-analysis of 60 RCTs on leg strength, whose abstract does not name a creatine form, found a small effect (effect size 0.24 for the legs overall) [5]; under the form rule, it does not count toward the rating.

In the brain, in 15 healthy men, two weeks of monohydrate raised frontal-lobe creatine by about 8% compared with placebo; the ATP signal fell, and phosphocreatine rose only slightly [6]. A systematic review (abstract without information on the form) confirms that supplementation raises brain creatine content, but only to a limited extent, and found inconsistent results for cognition [7]. Under sleep deprivation, a high single dose of monohydrate changed high-energy phosphates in the brain, prevented a drop in pH and improved performance and processing speed [8]. The first positive findings came from 45 young adults living vegetarian, in whom monohydrate clearly improved working memory and performance on an intelligence test [9]. The largest study to date, with 123 participants, did not find this effect at the same strength: working memory was just at the threshold of significance, the intelligence test was not; vegetarians did not benefit more, and side effects were more frequent with creatine [10]. A systematic review of six RCTs (abstract without information on the form) found signs of better short-term memory and reasoning, but no changes in young people [11]. A meta-analysis of eight RCTs that, according to the full text, included only studies with creatine monohydrate found a small benefit for memory (SMD 0.29), driven by older adults (66–76 years), not by younger ones; two authors declare ties to creatine manufacturers (former consulting, industry-funded research, creatine donations, advisory board membership) [12].

A review by the German Federal Institute for Risk Assessment lists gastrointestinal complaints, muscle cramps and weight gain as occasional adverse effects of creatine [13]. An older meta-analysis on kidney function concluded that creatine does not cause kidney damage, but presented higher serum creatinine and urea values contradictorily in the abstract [14]. A more recent meta-analysis of randomized studies only found a serum creatinine 0.13 milligrams per deciliter higher (95% CI 0.07–0.18), but no differences in urea and eGFR; studies longer than one year are lacking [15]. Neither abstract names a creatine form.

The EU has authorized two health claims for creatine: on physical performance in strength training during short-term, high-intensity exercise and, for adults over 55 doing regular resistance training, on the effect of the training on muscle strength [16]. Such a claim is a legal authorization, not an evidence level. According to the Commission's Novel Food Catalogue, creatine monohydrate is not considered a novel food; a German state authority and, for micronized monohydrate, the Spanish authority established this in the consultation procedure [17].

Formulations and origin: buffered creatine is not a distinct chemical form but is sold as monohydrate with an alkaline additive. In a double-blind RCT of 36 resistance-trained people over 28 days, a buffered product (Kre-Alkalyn) did not raise muscle creatine, body composition, strength or anaerobic performance more than monohydrate, either at the amount recommended by the manufacturer or at an amount equivalent to monohydrate; no fewer side effects were seen, and no side effects were reported in any group. The study was funded by a manufacturer of creatine monohydrate [18]. Micronized monohydrate is chemically the same compound and is listed in the same catalogue entry [17]; no comparative human data on micronization were found.

Synaptik serves solely to explain biochemistry and pharmacology and is not medical advice or a recommendation to take anything.

Mechanism of action only. Schematic longitudinal section through the edge of a skeletal muscle fibre with a capillary, not to scale. The figure alternates between rest with insulin and a short bout of exercise. Particles, speeds and the bars of the live readout are model outputs (illustrative) and only show the direction reported by the studies; the numbers in the readout and the text come from the studies cited.
Compound
View

insulin  glucose  H⁺  phosphocreatine  bicarbonate  compound  glow = active signalling node

Creatine enters the muscle cell via the creatine transporter (SLC6A8) [12] and is phosphorylated by creatine kinase to phosphocreatine, which regenerates ATP during exercise [10]. In a study without a placebo group, supplementation raised total creatine in the thigh muscle of 17 healthy people, most in those with low starting values and by as much as 50% in some; about a fifth of the creatine taken up was present as phosphocreatine, and ATP did not change [11]. In the model the phosphocreatine store is larger and empties more slowly during exercise.

Tap or focus a labelled part for a short explanation.

Also acting here, not drawn

Targets

TargetTypeActionKey dataEvidence
Creatine kinase / phosphocreatine store in skeletal muscleEnzymeBindingSubstrate of creatine kinase; muscle creatine rose under monohydrate over the course of the study (biopsy, comparison of forms without placebo) Human, non-randomised[1][18]
Creatine kinase / phosphocreatine store in the brainEnzymeBindingBrain creatine +8.1% (creatine/NAA) after 2 weeks (human, placebo comparison) Human, randomised[6]

Effect profile

Which signaling systems the compound affects according to current data. ↑ enhanced, ↓ dampened, ≈ modulated, ○ no effect; dots = evidence level.

  • Dopamineno data
  • Noradrenalineno data
  • Serotoninno data
  • Acetylcholineno data
  • Glutamate · AMPAno data
  • Glutamate · NMDAno data
  • GABAno data
  • Histamineno data
  • Orexinno data
  • Adenosineno data
  • Opioidsno data
  • Melatoninno data
  • Neurotrophinsno data
  • Blood flowno data
  • Nitric oxideno data
  • Energy metabolism↑ · more creatine in the brain, altered high-energy phosphates (MRS with a placebo group); phosphocreatine buffer in muscle[1][6][8]
  • Insulin · glucoseno data
  • Inflammation · oxidativeno data
  • Stress axisno data
  • Testosterone axisno data
  • Endocannabinoidsno data
  • Autophagy · senescenceno data
  • Immune systemno data
  • Lipid metabolismno data
  • Coagulation · fibrinolysisno data
  • Methylationno data

Routes of administration and bioavailability

How much of a compound reaches the blood or target tissue depends on the route into the body and on the dosage form. All routes of administration explained

  • Oral (swallowed) · Powder or capsules (monohydrate)

    not verified as a number in humans

    Plasma peak about one hour after intake [1]; muscle creatine rises over the course of the study [18], brain creatine to a limited extent [6][7].[6][7]

    Human, non-randomised

  • Oral (swallowed) · buffered (monohydrate with an alkaline additive)

    No advantage in muscle creatine over monohydrate in one RCT, funded by the monohydrate manufacturer [18].

    Human, randomised

Human studies

  • Meta-analysis of strength and lean mass during resistance training

    systematic review and three-level meta-analysis of 63 placebo-controlled RCTs · Adults doing resistance training, mostly young to middle-aged men · n = 1489

    Measured: Upper- and lower-body strength, lean mass, fat mass

    Result: Upper-body strength g 0.54 (CI 0.37–0.71), lower-body strength g 0.55 (without one outlier; 0.66 with it), lean mass g 0.30 (CI 0.18–0.41), fat mass n.s.; publication bias for strength, corrected g 0.36 and 0.35, respectively.[3]

    Human, randomised

  • Meta-analysis of body composition, monohydrate subgroup

    systematic review and dose-response meta-analysis of controlled studies (61 in total) · mixed: trained and untrained adults doing resistance training, also patient groups

    Measured: fat-free mass, body weight

    Result: Monohydrate subgroup: fat-free mass +1.35 kg (CI 1.05–1.64), body weight +0.87 kg (CI 0.75–1.00).[4]

    Human, randomised

  • Meta-analysis of leg strength (without information on the form)

    systematic review and meta-analyses of 60 placebo-controlled RCTs · mixed · n = 1297

    Measured: Strength of the lower extremities (exertions under 3 minutes)

    Result: Effect size for the legs overall 0.24 (CI 0.13–0.35); squat 0.34, leg press 0.30. Does not count toward the rating (no information on the form in the abstract).[5]

    Human, randomised

  • Meta-analysis of memory in healthy people

    systematic review and meta-analysis of RCTs (8 in the meta-analysis), creatine monohydrate only · healthy · 5 days to 24 weeks

    Measured: Memory measures

    Result: SMD 0.29 (95% CI 0.04–0.53); older adults SMD 0.88, younger adults SMD 0.03; high heterogeneity.[12]

    Human, randomised

  • Largest RCT, vegetarians and mixed-diet eaters

    RCT, double-blind, placebo-controlled, crossover, preregistered · healthy · n = 123 · 2 × 6 weeks

    Measured: Raven's matrices, backward digit span

    Result: Digit span p = 0.064, Raven's matrices not significant; side effects more frequent (RR 4.25).[10]

    Human, randomised

  • Young adults living vegetarian

    RCT, double-blind, placebo-controlled, crossover · healthy (vegetarian) · n = 45 · 6 weeks

    Measured: Backward digit span, Raven's matrices

    Result: Marked improvement on both tests (p < 0.0001).[9]

    Human, randomised

  • Single dose under sleep deprivation

    placebo-controlled · healthy · single dose, 21 hours of sleep deprivation

    Measured: 31P/1H MRS, cognitive tests

    Result: Altered high-energy phosphates, no drop in pH, better performance and processing speed.[8]

    Human, randomised

  • MRS in healthy men

    placebo-controlled · healthy (men) · n = 15 · 14 days

    Measured: Creatine, ATP, phosphocreatine in the brain

    Result: Creatine +8.1%, β-NTP −7.8%, phosphocreatine +3.4% (borderline).[6]

    Human, randomised

  • Meta-analysis of kidney function (RCTs)

    systematic review and meta-analysis of 19 RCTs and one randomized crossover study · mixed · under and over one month

    Measured: Serum creatinine, urea, eGFR

    Result: Creatinine +0.13 milligrams per deciliter (CI 0.07–0.18); urea and eGFR without difference. Abstract without information on the form.[15]

    Human, randomised

  • Buffered creatine versus monohydrate

    RCT, double-blind, three arms without placebo · healthy (resistance-trained) · n = 36 · 28 days

    Measured: Muscle creatine (biopsy), body composition (DEXA), maximal strength, anaerobic performance

    Result: No benefits of the buffered product; muscle creatine tended to be higher under monohydrate than at the manufacturer's amount (p = 0.053). Funded by the monohydrate manufacturer.[18]

    Human, randomised

  • Creatine in the thigh muscle

    without a control group · healthy · n = 17 · 2 days and longer

    Measured: Total creatine, phosphocreatine and ATP in the quadriceps

    Result: Total creatine increased, most strongly with a low baseline value, by up to 50% in some; about 20% or more of the creatine taken up as phosphocreatine; ATP unchanged.[19]

    Human, non-randomised

Risks and warnings

  • Weight gain and water retention

    According to the position statement, weight gain is the only regularly reported side effect; at the start, creatine briefly retains some water [1]. In the monohydrate subgroup of a meta-analysis, body weight rose by 0.87 kg compared with placebo [4].

    Human, randomised

  • Gastrointestinal complaints, muscle cramps and other side effects

    The German Federal Institute for Risk Assessment lists occasional gastrointestinal complaints, muscle cramps and weight gain [13]. In the largest cognition study, side effects were reported more often under creatine than under placebo (RR 4.25) [10].

    Human, randomised

  • Creatinine rise and kidney values

    Creatine raises serum creatinine; in a meta-analysis of randomized studies, urea and eGFR remained unchanged, and long-term studies beyond one year are lacking [15]. An older meta-analysis presents the laboratory values contradictorily [14]. Neither abstract names a creatine form. Case reports of apparent kidney failure are described for creatine ethyl ester (see there), not in these sources for monohydrate.

    Human, randomised

Fact check: common claims

  • partly supported

    “Creatine makes you smarter”

    Small memory benefit in a meta-analysis with monohydrate, mainly in older adults [12]; hardly any effect in young healthy people [11][12], largest RCT only borderline [10].

  • partly supported

    “Vegetarians benefit especially from creatine cognitively”

    Strong effects in an early study with vegetarians [9] and better memory according to a review [11]; in the largest study, however, no difference from mixed-diet eaters [10].

  • partly supported

    “Creatine helps against mental fatigue during sleep deprivation”

    One placebo-controlled study with a high single dose showed better performance under sleep deprivation [8]; confirmation by other groups is still pending.

  • not supported

    “Creatine damages the kidneys”

    In randomized studies, only serum creatinine rose, while urea and eGFR remained unchanged [15]; the older meta-analysis also found no signs of kidney damage [14]. Long-term data beyond one year are lacking [15].

  • not supported

    “Buffered creatine works better and has fewer side effects than monohydrate”

    In the only RCT found, no advantage in muscle creatine, body composition, strength and anaerobic performance and no fewer side effects; the study was funded by a monohydrate manufacturer [18].

  • not supported

    “Newer forms of creatine are utilized better than monohydrate”

    A critical review found no documented advantage in bioavailability or efficacy for any other form; the authors have ties to monohydrate manufacturers [2]. Details in the profiles of the other forms.

Pharmacokinetics

Absorption
By mouth; plasma peak about one hour after intake [1]. Uptake into the brain is limited, usually measurable only after weeks [7][8].
Half-life
Not verified.
Metabolism
Non-enzymatic breakdown to creatinine, about 1–2% of muscle creatine per day, excretion in the urine; endogenous synthesis via AGAT and GAMT [1].
Entry into the brain
Brain creatine rises measurably, but to a limited extent (MRS) [6][7].

Legal status

Germany
A German state authority classified creatine monohydrate as not novel in the consultation procedure on novel food status (according to the Novel Food Catalogue) [17]. Marketing authorizations as a medicinal product (AMIce) were not checked (not verified).
EU
According to the Commission's Novel Food Catalogue, it is not considered a novel food, including as micronized monohydrate (entry POL-NF-08683, retrieved October 25, 2026); the catalogue is a guidance tool, not a legal act [17]. Two health claims are authorized for creatine (see health_claims) [16]; according to a review, monohydrate is the only creatine source with authorized claims in the EU [2].
USA
Not verified.
Other countries
One of the most widely used sports nutrition products [1].

Authorised EU health claims

EU claim authorised An authorised health claim is a legal statement about the nutrient, not about this form, and not a level of evidence. The evidence for this form is reported separately under the main claim and in the human studies.

  • “Creatine increases physical performance in successive bursts of short-term, high intensity exercise”

    Nutrient
    Creatine
    Legal basis
    Regulation (EU) No 432/2012[16]
    Reading
    legally permitted; close in content to the promise “More strength and muscle mass with training” (see there for rating and result). The conditions of use specify a daily amount and the target group of adults doing high-intensity physical exercise.

  • “Daily creatine consumption can enhance the effect of resistance training on muscle strength in adults over the age of 55”

    Nutrient
    Creatine
    Legal basis
    Regulation (EU) No 432/2012, inserted by Implementing Regulation (EU) 2017/672[3][16]
    Reading
    legally permitted; the profile contains no separate assessment for people over 55. In the meta-analysis [3], the strength effect in adults aged 60 years and older was significant and only slightly smaller than in younger adults; it was not significant only in the 45- to 59-year-olds (four effect sizes). The authors regard the age pattern as exploratory. The conditions require regular resistance training and specify a daily amount.

Related compounds

Acetyl-L-Carnitinsame class (German only)Kreatin-Hydrochloridother form (German only)Kreatin-Ethylesterother form (German only)Kreatin-Nitratother form (German only)Kreatin-Citratother form (German only)Kreatin-Pyruvatother form (German only)Guanidinoessigsäure (GAA)prodrug (German only)

Open questions

  • How large is the strength effect after correction for publication bias in large, preregistered studies, and how strongly does it decline with age?
  • How much creatine does the brain have to take up for a cognitive effect to become measurable?
  • Can the memory benefit in older adults be confirmed in large, preregistered studies?
  • How does intake over many years affect kidney function, measured with creatinine-independent methods?

References

  1. Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18. doi:10.1186/s12970-017-0173-z · PubMed
  2. Kreider RB, Jäger R, Purpura M. Bioavailability, efficacy, safety, and regulatory status of creatine and related compounds: a critical review. Nutrients. 2022;14(5):1035. doi:10.3390/nu14051035 · PubMed
  3. Wang H, Wang H, Xin X, Yi Z. Resistance training combined with creatine supplementation: a three-level meta-analysis of multidimensional outcomes from strength enhancement to body composition remodeling. J Int Soc Sports Nutr. 2026;23(sup1):2718316. doi:10.1080/15502783.2026.2718316 · PubMed
  4. Ashtary-Larky D, Mohammadi S, Hajizadeh L, Mousavi SAH, Forbes SC, Candow DG, et al. Creatine supplementation and resistance training: a comparison between novice and experienced lifters – a systematic review and dose-response meta-analysis. J Int Soc Sports Nutr. 2025;22(sup1):2586523. doi:10.1080/15502783.2025.2586523 · PubMed
  5. Lanhers C, Pereira B, Naughton G, Trousselard M, Lesage FX, Dutheil F. Creatine supplementation and lower limb strength performance: a systematic review and meta-analyses. Sports Med. 2015;45(9):1285–94. doi:10.1007/s40279-015-0337-4 · PubMed
  6. Lyoo IK, Kong SW, Sung SM, Hirashima F, Parow A, Hennen J, et al. Multinuclear magnetic resonance spectroscopy of high-energy phosphate metabolites in human brain following oral supplementation of creatine-monohydrate. Psychiatry Res. 2003;123(2):87–100. doi:10.1016/s0925-4927(03)00046-5 · PubMed
  7. McMorris T, Hale BJ, Pine BS, Williams TB. Creatine supplementation research fails to support the theoretical basis for an effect on cognition: evidence from a systematic review. Behav Brain Res. 2024;466:114982. doi:10.1016/j.bbr.2024.114982 · PubMed
  8. Gordji-Nejad A, Matusch A, Kleedörfer S, Jayeshkumar Patel H, Drzezga A, Elmenhorst D, et al. Single dose creatine improves cognitive performance and induces changes in cerebral high energy phosphates during sleep deprivation. Sci Rep. 2024;14(1):4937. doi:10.1038/s41598-024-54249-9 · PubMed
  9. Rae C, Digney AL, McEwan SR, Bates TC. Oral creatine monohydrate supplementation improves brain performance: a double-blind, placebo-controlled, cross-over trial. Proc Biol Sci. 2003;270(1529):2147–50. doi:10.1098/rspb.2003.2492 · PubMed
  10. Sandkühler JF, Kersting X, Faust A, Königs EK, Altman G, Ettinger U, et al. The effects of creatine supplementation on cognitive performance – a randomised controlled study. BMC Med. 2023;21(1):440. doi:10.1186/s12916-023-03146-5 · PubMed
  11. Avgerinos KI, Spyrou N, Bougioukas KI, Kapogiannis D. Effects of creatine supplementation on cognitive function of healthy individuals: a systematic review of randomized controlled trials. Exp Gerontol. 2018;108:166–73. doi:10.1016/j.exger.2018.04.013 · PubMed
  12. Prokopidis K, Giannos P, Triantafyllidis KK, Kechagias KS, Forbes SC, Candow DG. Effects of creatine supplementation on memory in healthy individuals: a systematic review and meta-analysis of randomized controlled trials. Nutr Rev. 2023;81(4):416–27. doi:10.1093/nutrit/nuac064 · PubMed
  13. Andres S, Ziegenhagen R, Trefflich I, Pevny S, Schultrich K, Braun H, et al. Creatine and creatine forms intended for sports nutrition. Mol Nutr Food Res. 2017;61(6):1600772. doi:10.1002/mnfr.201600772 · PubMed
  14. de Souza E Silva A, Pertille A, Reis Barbosa CG, Aparecida de Oliveira Silva J, de Jesus DV, Ribeiro AGSV, et al. Effects of creatine supplementation on renal function: a systematic review and meta-analysis. J Ren Nutr. 2019;29(6):480–9. doi:10.1053/j.jrn.2019.05.004 · PubMed
  15. Tsiaras A, Loufopoulos G, Theodoridis X, Liakopoulos V, Poulia KA, Chourdakis M. The effect of creatine supplementation on kidney function: a systematic review and meta-analysis of randomized controlled trials. J Ren Nutr. 2026 [online vor Druck]. doi:10.1053/j.jrn.2026.04.010 · PubMed
  16. Verordnung (EU) Nr. 432/2012 der Kommission vom 16. Mai 2012 zur Festlegung einer Liste zulässiger anderer gesundheitsbezogener Angaben über Lebensmittel als Angaben über die Reduzierung eines Krankheitsrisikos sowie die Entwicklung und die Gesundheit von Kindern. ABl. L 136 vom 25.5.2012, S. 1. Konsolidierte Fassung vom 20.08.2025 (CELEX 02012R0432-20250820), Einträge „Kreatin“.
  17. Europäische Kommission. Novel Food Status Catalogue: Creatine monohydrate [Datenbank]. POL-NF-08683 [zitiert 25.10.2026]. Verfügbar unter: https://ec.europa.eu/food/food-feed-portal/screen/novel-food-catalogue/search
  18. Jagim AR, Oliver JM, Sanchez A, Galvan E, Fluckey J, Riechman S, et al. A buffered form of creatine does not promote greater changes in muscle creatine content, body composition, or training adaptations than creatine monohydrate. J Int Soc Sports Nutr. 2012;9(1):43. doi:10.1186/1550-2783-9-43 · PubMed
  19. Harris RC, Söderlund K, Hultman E. Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clin Sci (Lond). 1992;83(3):367–74. doi:10.1042/cs0830367 · PubMed
How this profile was checked

Last reviewed: 2026-10-25. All sources with a DOI or PMID were resolved automatically via Crossref or doi.org and PubMed.

Translated from the German profile (version of 2026-10-25); translation checked on 2026-10-26.

Checked

  • October 25, 2026 (muscle figure): [19] checked against the abstract (PubMed): 17 people, total creatine in the quadriceps increased, by up to 50% in some, about 20% or more as phosphocreatine, ATP unchanged; no placebo group. Form according to the abstract creatine monohydrate (form rule met). DOI resolved via Crossref.
  • All PMIDs resolved via PubMed efetch; DOIs taken from the PubMed records and checked via Crossref with tools/pruefe_profile.py.
  • Restructuring wave 3 (October 25, 2026): new main promise strength and muscle mass, cognition moved to position 2; family kreatin-formen; references renumbered in order of first mention. The figures of the previous references (now [6]–[12], [14]) confirmed again against the abstract: 15 men, creatine +8.1%, β-NTP −7.8%, PCr +3.4% [6]; single dose under sleep deprivation [8]; 45 vegetarians, p < 0.0001 [9]; 123 people, p = 0.064, RR 4.25 [10]; 6 RCTs, 281 people [11]; SMD 0.29, older adults 0.88, younger adults 0.03 [12]; creatinine SMD 0.48 [14].
  • Form rule (K2, in essence): monohydrate documented by title or abstract for [6], [8], [9]; by full text for [10] (methods: monohydrate powder) and [12] (inclusion criterion “Creatine monohydrate supplementation”). [7], [11], [14], [15] and [5] name no form in the abstract and do not count toward rating, result and systeme; [7] was therefore removed from systeme and the evmap in the cross-check.
  • Full text [3] (PMC13600305): inclusion of only RCTs with placebo and resistance training, no combinations with other active substances; population according to PICOS “adults aged ≥18 years”; results section (section “Characteristics of included studies”) “All studies used creatine monohydrate,” discussion “the vast majority of included studies used creatine monohydrate”; upper-body strength g 0.54 (CI 0.37–0.71), lower-body 0.55 (0.38–0.71) after excluding one outlier (influence analysis; with it 0.66, CI 0.47–0.85), after trim-and-fill 0.36 and 0.35, respectively; age subgroups upper body 0.62 (18–44 years), −0.10 (45–59 years, K = 4), 0.52 (60 years and older), lower body 0.65, −0.10, 0.52, described by the authors as exploratory; lean mass 0.30 (0.18–0.41); GRADE low to moderate; no conflicts of interest declared.
  • Full text [4] (PMC12777911), Table 2: CrM subgroup fat-free mass 1.35 kg (CI 1.05–1.64), body weight 0.87 kg (CI 0.75–1.00); Table 1 also contains monohydrate arms in patients (knee osteoarthritis, osteopenia or osteoporosis, after stroke, HIV infection), hence population “mixed: …”; COI statement in the PubMed record (consulting for creatine suppliers, creatine donations, research funding, advisory board membership).
  • Abstract [5]: 60 studies, 646 versus 651 people, legs overall ES 0.235 (CI 0.125–0.346), squat 0.336, leg press 0.297; no information on the form; full text not freely accessible.
  • Full text [1] (PMC5469049): synthesis via AGAT/GAMT, 95% in skeletal muscle, two thirds as PCr, 1–2% breakdown to creatinine per day, plasma peak after about 60 minutes, weight gain as the only regularly reported side effect, short-term water retention; funding by the Council for Responsible Nutrition, conflicts of interest of several authors (consulting, industry funding).
  • Full text [2] (PMC8912867): creatine content by mass (monohydrate 87.9%), assessment of the forms, monohydrate as the only form with authorized EU claims; COI: two authors with former, expired creatine patents as employees of a creatine manufacturer, first author chair of an advisory board of this manufacturer.
  • Full text [12] (PMC9999677), Declaration of interest: one author former scientific advisor to a company that sold creatine; one author with industry-funded creatine research, creatine donations, travel support and a seat on the scientific advisory board of a creatine manufacturer; no external funding.
  • Abstract [13] (German Federal Institute for Risk Assessment): gastrointestinal complaints, muscle cramps, weight gain; amounts not included.
  • Abstract [15]: 19 RCTs and one randomized crossover study, creatinine MD 0.13 mg/dl (CI 0.07–0.18), urea MD −0.60, eGFR MD −5.20 (CI −15.00 to 4.60), no differences by duration; no sign of apparent kidney failure (sentence on this removed in the cross-check).
  • Full text [18] (PMC3479057): funding by a manufacturer of creatine monohydrate (research grant to the university); first author group declared to have no financial interest in the outcome.
  • Regulation (EU) No 432/2012, consolidated version of August 20, 2025 (Cellar XHTML): both creatine entries present (short-term strength, base version; over 55 years, inserted by Implementing Regulation (EU) 2017/672, whose text was also read). Amounts from the conditions of use not included.
  • Novel Food Catalogue (Commission backend API, 979 entries, retrieved October 25, 2026): POL-NF-08683 “Creatine monohydrate,” status “not novel in food” (German state authority; micronized monohydrate: Spanish authority). Union list (CELEX 02017R2470-20260810): no hit for “Kreatin”/“Creatin.” AMVV Annex 1 (German federal legal portal, retrieved October 25, 2026): no entry for creatine.
  • PubChem: CID 80116 (monohydrate), C4H11N3O3.

Not verified

  • Whether all 63 studies in [3] actually used monohydrate (results and discussion sections contradict each other); individual studies not checked.
  • Number of studies or effect sizes in the monohydrate subgroup of [4] (table column not clearly labeled); [4] also included non-randomized controlled studies and patient groups; whether the studies included in [3] contain patients was not checked individually.
  • Number of cases in [8] and number of participants in the meta-analysis [12] not given in the abstract.
  • Creatine form in the meta-analyses [14] and [15] and the review [13] (abstract only checked).
  • Drug status in Germany (AMIce) and legal status in the US not checked.

No dosages, no sources of supply. This information does not replace medical advice.

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