Does creatine actually build muscle or just water?

Both, in different proportions over time. The first 1–2 weeks of supplementation increase intracellular water retention as muscle creatine stores rise — this accounts for an early body mass increase of 0.5–1.5 kg, which is largely water. Over weeks 4–12 of supplementation combined with resistance training, controlled trials consistently report additional lean mass gains relative to placebo groups, indicating that contractile tissue (muscle protein) also increases. The mechanism appears to be improved training capacity: by buffering phosphocreatine more effectively, creatine allows higher training volumes and intensities, which drive the muscle protein synthesis stimulus.

Is creatine safe for kidneys?

Yes, in healthy adults. The most-cited concern — elevated serum creatinine in supplemented individuals — reflects increased dietary creatine throughput rather than reduced kidney function. Direct measurements of glomerular filtration rate (GFR) show no adverse effect of creatine supplementation in healthy adults. A meta-analysis of 21 trials (PMID: 41199218) confirmed no significant adverse effects on kidney function. The ISSN position stand (PMID: 28615996) characterises supplementation up to 30 g/day for up to 5 years as safe in healthy individuals. Anyone with pre-existing kidney disease should consult their GP before starting any creatine supplement.

Does creatine cause hair loss?

No controlled trial has demonstrated that creatine causes hair loss. The hair-loss claim originated from a single 2009 trial in young rugby players (PMID: 19741313) that reported elevated serum dihydrotestosterone (DHT) — but the trial did not measure or report any actual hair loss, and the DHT finding has not been replicated in subsequent trials. The ISSN position stand and broader review literature do not list hair loss as a recognised adverse effect of creatine.

Should women take creatine?

The trial evidence supports creatine supplementation in women on the same indications as men: high-intensity exercise performance, resistance training adaptations, and lean mass gains. Effect sizes in female participants are broadly comparable to male participants in trials that include both, although the proportion of female participants in the historical creatine literature has been lower than male participants. A growing body of literature specifically examines creatine in postmenopausal women in combination with resistance training and reports favourable effects on lean mass, strength, and possibly bone health. Always consult a UK GP if you are pregnant, planning pregnancy, or breastfeeding before starting creatine.

Does creatine help cognitive function?

The cognitive evidence is most consistent under conditions of stress, sleep deprivation, and in low-baseline-creatine populations such as vegetarians. A 2024 systematic review (PMID: 39070254) found significant improvements in working memory and reasoning tasks under sleep-deprivation and acute-stress conditions, with smaller and less consistent effects in well-rested general adult populations. The ISSN position stand acknowledges the cognitive evidence as promising but less mature than the exercise-performance evidence. It is reasonable, on current evidence, to expect cognitive benefit under stress and uncertain benefit at rest.

How long until creatine 'works'?

Muscle creatine saturation determines when performance benefits emerge. Without a loading phase, daily supplementation at 5 g/day reaches saturation over approximately 3–4 weeks. With a loading phase (typically 0.3 g/kg/day, divided into 4 doses, for 5–7 days, then 5 g/day maintenance), saturation is reached within approximately 1 week. Performance and lean-mass effects in trials are typically measurable by week 4 and continue to accrue through weeks 4–12 of combined supplementation and resistance training.

Should I cycle creatine?

No. There is no controlled trial evidence that periodic breaks from creatine supplementation produce any benefit. The ISSN position stand explicitly addresses this point: muscle creatine stores will deplete back towards baseline over approximately 4–6 weeks after stopping supplementation, and there is no recovery, sensitisation, or other mechanism that benefits from cycling. Continuous daily use at 3–5 g/day is the protocol supported by the evidence.

Is loading necessary?

Loading is not necessary. The loading phase (0.3 g/kg/day for 5–7 days, then 5 g/day) reaches muscle creatine saturation faster — within approximately 1 week rather than 3–4 weeks at maintenance dosing alone — but the eventual saturation point is the same. The performance and lean-mass benefits are equivalent at saturation regardless of how saturation was reached. Loading does increase the incidence of mild GI discomfort during the loading phase. For most users, simple 5 g/day from day one is sufficient and well-tolerated.

Does Creatine Actually Work? An Evidence Review

Nutripedia Research Team26 March 2026

Updated 24 April 2026

Creatine monohydrate is one of the most-studied dietary supplements in the published literature. We summarise the meta-analyses, effect sizes, the kidney-safety record, and the populations where the evidence is strongest.

Not medical advice

Nutripedia summarises published peer-reviewed research. This content is for informational purposes only and is not a substitute for professional medical advice. Product mentions are not endorsements.

What the Body of Evidence Shows

Creatine monohydrate is one of the most-studied dietary supplements in the published literature. The active research base spans more than 500 peer-reviewed human studies covering exercise performance, body composition, cognitive function, and safety endpoints, with controlled trials extending back to the early 1990s. The most authoritative consensus document is the International Society of Sports Nutrition (ISSN) Position Stand on creatine, originally published in 2007 and updated in 2017 (Kreider RB, Kalman DS, Antonio J et al., PMID: 28615996). The Position Stand reviews the cumulative trial evidence and concludes, in the authors' words, that creatine monohydrate is "the most effective ergogenic nutritional supplement currently available to athletes with the intent of increasing high-intensity exercise capacity and lean body mass during training". The headline conclusions across the position stand and supporting meta-analyses are: 1. Creatine monohydrate, taken at 3–5 g/day, increases muscle phosphocreatine stores by approximately 10–40% above baseline, depending on starting concentration and dose protocol. 2. Performance benefits are most consistently observed in repeated bouts of high-intensity exercise lasting up to 30 seconds with short rest intervals — sprinting, resistance training, jumps, and Wingate-type protocols. 3. Lean body mass typically increases by 0.5–2.0 kg over 4–12 weeks of supplementation combined with resistance training, relative to placebo. 4. Long-term safety is well-established at supplementation doses up to 30 g/day for up to 5 years in healthy individuals. 5. No alternative form (HCl, ethyl ester, buffered, magnesium chelate, nitrate) has demonstrated superior efficacy to monohydrate. Monohydrate remains the recommended form. For a deeper dive into the underlying clinical literature, see the [creatine monohydrate item page](/items/creatine-monohydrate).

Our research is based on 83 peer-reviewed studies. View the full evidence database

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Nutripedia is an educational resource. Content is sourced from peer-reviewed studies and does not constitute medical advice. Product mentions are not endorsements. Consult a healthcare professional before starting any supplement.

Reviewed by

Archie Roberts

Founder, Nutripedia — ALDR Ltd

This page summarises published research from PubMed, NHS, EFSA, and SACN. It does not constitute medical advice; consult a qualified healthcare professional before changing any supplement regimen.

Last reviewed: 24 Apr 2026Methodology