More than 500 scientific publications have studied creatine, one of the best-documented supplements in sports nutrition. Yet persistent rumours follow it: damaged kidneys, hair loss and water retention. Here is what trials show, what the European Union permits manufacturers to say and how to take it.
Key takeaways
- The EU permits two creatine claims at 3 g per day, including one restricted to people over 55 who practise resistance training.
- In a meta-analysis of 35 trials, creatine combined with resistance training added an average of 1.1 kg of lean mass compared with placebo.
- 3 g per day for 28 days increases muscle creatine as much as 20 g per day for 6 days.
- In healthy people, it raises blood creatinine without demonstrated kidney damage.
What exactly is creatine?
Creatine is a small molecule made mainly by the kidneys and liver from three amino acids: arginine, glycine and methionine. Like taurine, it is also supplied by meat and fish. Around half our requirements, approximately 2 g per day, are covered by food.
Around 95% of creatine is in muscle, two-thirds as phosphocreatine. During very intense, short efforts such as a sprint or heavy set, it recharges ATP, the molecule supplying energy for contraction. Creatine also shuttles to and from mitochondria, where ATP is made with the help of NAD+.
What do European regulations say about creatine?
The European register under Regulation No 432/2012 permits two health claims for creatine, none for endurance or the brain. Here is their exact wording.
- “Creatine increases physical performance in successive bursts of short-term, high intensity exercise.” Conditions: 3 g per day, in a product intended for adults performing high-intensity exercise.
- “Daily creatine consumption can enhance the effect of resistance training on muscle strength in adults over the age of 55.” Conditions: 3 g per day, with resistance training at least three times weekly for several weeks, using progressive loads at an intensity of at least 65 to 75% of the maximum load lifted once.
Which effects have studies demonstrated?
Real but modest effects. Several authors of texts from the ISSN, a sports nutrition scientific society, declare links with manufacturers; some also co-author two cited meta-analyses. We therefore compare these with health agencies' assessments.
Strength, lean mass and repeated sprints
A 2025 meta-analysis of 69 randomised trials with 1,937 participants shows that, with resistance training, creatine improves bench press by an average of 1.4 kg and squat by 5.6 kg compared with placebo. It does not significantly change grip strength, and gains are more consistent in young adults and men. Another analysis of 35 trials measures 1.1 kg more lean mass with resistance training, regardless of age. For repeated sprints, a meta-analysis of 14 trials finds higher mean power, but neither higher peak power nor less fatigue.
After age 55 and in vegetarians
After age 55, the claim rests on trials combining daily creatine with resistance training. Without exercise, results disappoint: in postmenopausal women, 3 g per day for two years did not increase lean mass. Strength gains are also more modest in older people.
Vegetarians have lower stores: 90 to 110 mmol/kg of dry muscle, compared with around 120. According to a review of 9 studies, supplementation raises these stores, with lean mass and strength gains, although it is unknown whether the benefit exceeds that in omnivores. The studies' risk of bias is moderate to high.
How to take creatine: dose, loading and timing
Two strategies fill muscle stores. Their main difference is speed.
| Strategy | Dose | Full stores | What to know |
|---|---|---|---|
| Loading phase | 20 g/day in 4 doses for 5 to 7 days, then 3 to 5 g/day | In 5 to 7 days | Rapid weight gain from water |
| Daily dose | 3 to 5 g/day from the start | In around 4 weeks | Same result, more gradual |
In a reference trial, 20 g per day for 6 days and 3 g per day for 28 days both increased muscle creatine by around 20%. During loading, divide the doses: more than 10 g at once can cause diarrhoea.
Timing matters little: according to a 2021 review, the few trials comparing use before or after training contradict each other. What matters is consistency, including rest days. Creatine is retained better when taken with a meal containing carbohydrate, or carbohydrate and protein.
Monohydrate or other forms: which should you choose?
Creatine monohydrate is the reference form in studies. It contains 87.9% creatine, of which around 99% is absorbed. Newer forms such as salts, ethyl ester, buffered creatine and nitrate have not shown better muscle uptake at an equal amount in any published study.
As with magnesium, the most promoted form is not necessarily the best studied. Powder or capsules contain the same molecule; only the amount per dose changes.
Creatine myths: what do studies say?
Most do not hold up in trials in healthy people. Some, however, contain an element of truth.
| Myth | What studies show | Verdict |
|---|---|---|
| “It damages the kidneys” | Creatinine rises; measured filtration is unchanged | False if kidneys are healthy |
| “It causes hair loss” | One 2009 hormone study, never replicated | Not demonstrated |
| “It makes you swell” | Water stored during loading, not fat | True only at first |
| “It causes cramps” | No more cramps in studies | False |
| “It is a doping substance” | Banned by no sporting body | False |
| “It is useless for women” | Smaller gains; women little studied | Needs qualification |
Does creatine damage the kidneys?
Not in healthy people at the doses studied. However, creatine turns into creatinine, the blood marker of kidney function. ANSES notes that blood testing may then falsely suggest kidney failure. A 2026 meta-analysis of 26 trials with 1,036 participants, healthy or with kidney disease, finds creatinine higher by 0.14mg/dl and consequently lower estimated filtration. Directly measured filtration does not change.
According to ANSES, the small or short available studies do not rule out a long-term kidney effect. With kidney disease, diabetes or removal of a kidney, ANSES discourages creatine. Mention its use before a blood test.
Does it cause hair loss?
This concern comes from one 2009 study in 20 rugby players. After 7 days at 25 g, then 14 days at 5 g per day, their DHT, a testosterone-derived hormone involved in baldness, remained 40% above baseline (+56% after loading). Testosterone did not change. No hair was examined, values remained normal and the result has never been replicated.
In 2025, a randomised trial measured hair: in 38 trained men, 5 g per day for 12 weeks changed neither DHT nor hair density, number or thickness. This is reassuring, but the trial is small and short, and some authors have industry links.
Water retention, weight gain and cramps
The loading phase often adds 1 to 3 kg in a few days, mainly water stored in muscle. Over several weeks, body water remains proportional to muscle mass and fat mass does not increase. For cramps, a non-randomised study in 72 American football players in hot weather recorded fewer in those taking creatine.
Women, adolescents and doping
Women have been studied little: their lean mass and strength gains are smaller or non-significant, perhaps because initial stores are higher. After menopause, trials with resistance training report mass and strength gains. Human pregnancy data are very limited, and ANSES discourages bodybuilding supplements in pregnant or breastfeeding women.
ANSES also discourages these supplements in adolescents; the ISSN considers creatine acceptable in young athletes under conditions such as supervised competitive training, a balanced diet and recommended doses. No sporting body bans creatine: the anti-doping risk comes from contaminated products.
Creatine and the brain: what does research show?
Results remain uncertain. A 2024 meta-analysis of 16 trials with 492 adults finds a small effect on memory, attention and processing speed, but not overall cognition, with clearer benefits in people who are ill and in women. However, after examining 23 studies, EFSA concluded in 2024 that no cause-and-effect relationship was established: the working memory effect appeared only at 20 g per day for 5 to 7 days. It also criticises this meta-analysis for counting the same participants several times.
Other approaches have been tested more thoroughly: see the most effective methods for memory. Other nutrients are also studied, such as choline, an acetylcholine precursor.
Powder purity: what should you watch for?
Not all powders are equal. According to 2007 industry data cited by the ISSN, some creatine products contained manufacturing impurities such as dicyandiamide, dihydrotriazine and heavy metals, whose health effects were unknown. ANSES also notes that sports supplements, particularly those bought online, may contain undeclared doping substances. It advises reading the composition, choosing controlled distribution channels and, for athletes, products complying with NF V 94-001, a standard addressing this risk.
Frequently asked questions
Creatine, creatinine and CPK: what is the difference?
Creatine is stored in muscle. Creatinine is its breakdown product, eliminated by the kidneys and measured to estimate their function. CPK, or creatine kinase, is the enzyme exchanging energy between phosphocreatine and ATP; its blood level rises when muscle fibres are damaged.
Which foods contain creatine?
Mainly red meat and seafood. A 170 g serving of meat provides around 0.7 g, and 450 g of raw beef or salmon provides 1 to 2 g.
Is creatine useful without exercise?
Only a little. In a meta-analysis of 35 trials, creatine taken without training did not change lean mass (+0.03 kg, not significant). Its effects work through training: a little more work in a series of repetitions or sprints.
Do you need breaks?
There is no requirement. On stopping, stores return to baseline in 4 to 6 weeks, without a lasting reduction in natural production. In athletes, continuous use for up to three years showed no notable adverse effect.
Can you prepare your drink in advance?
It is best drunk promptly. In powder form, creatine stays stable for years; once dissolved, it gradually turns into creatinine, faster if the drink is hot or acidic.
Can it be combined with other supplements or medication?
ANSES discourages combining several sports supplements or taking them with medication without medical advice, because interactions are poorly known. Tell your doctor and pharmacist about any use.
Conclusion
Creatine has well-documented but targeted, modest effects: in studies, a little more strength, lean mass and power during brief, repeated efforts, particularly with resistance training. Trials use 3 to 5 g of monohydrate per day. Rumours about kidneys, hair or cramps do not hold up against data in healthy people, but caution is needed with kidney disease, pregnancy and adolescents. For the brain, nothing is established.
Sources
- ANSES (2016). Food supplements for athletes: opinion and collective expert report on the risks of consuming sports supplements intended to develop muscle or reduce fat mass (request 2014-SA-0008). Maisons-Alfort: ANSES. anses.fr
- European Commission (2012). Regulation (EU) No 432/2012 of 16 May 2012 establishing a list of permitted health claims made on foods, other than those referring to the reduction of disease risk and to children's development and health. Official Journal of the European Union, L 136, 1–40; consolidated version of 19 August 2024, incorporating Implementing Regulation (EU) 2017/672. eur-lex.europa.eu
- EFSA NDA Panel (2024). Creatine and improvement in cognitive function: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006. EFSA Journal, 22(11), e9100. doi:10.2903/j.efsa.2024.9100
- Kreider RB et al. (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 14, 18. doi:10.1186/s12970-017-0173-z
- Antonio J et al. (2021). Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? Journal of the International Society of Sports Nutrition, 18(1), 13. doi:10.1186/s12970-021-00412-w
- Kazeminasab F et al. (2025). The effects of creatine supplementation on upper- and lower-body strength and power: a systematic review and meta-analysis. Nutrients, 17(17), 2748. doi:10.3390/nu17172748
- Delpino FM et al. (2022). Influence of age, sex, and type of exercise on the efficacy of creatine supplementation on lean body mass: a systematic review and meta-analysis of randomized clinical trials. Nutrition, 103-104, 111791. doi:10.1016/j.nut.2022.111791
- Glaister M, Rhodes L (2022). Short-term creatine supplementation and repeated sprint ability: a systematic review and meta-analysis. International Journal of Sport Nutrition and Exercise Metabolism, 32(6), 491-500. doi:10.1123/ijsnem.2022-0072
- Kaviani M et al. (2020). Benefits of creatine supplementation for vegetarians compared to omnivorous athletes: a systematic review. International Journal of Environmental Research and Public Health, 17(9), 3041. doi:10.3390/ijerph17093041
- Ribeiro F et al. (2021). Timing of creatine supplementation around exercise: a real concern? Nutrients, 13(8), 2844. doi:10.3390/nu13082844
- de Souza Almeida A et al. (2026). Impact of creatine supplementation on kidney health: a systematic review and meta-analysis. International Urology and Nephrology, online ahead of print. doi:10.1007/s11255-026-05287-x
- van der Merwe J et al. (2009). Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players. Clinical Journal of Sport Medicine, 19(5), 399-404. doi:10.1097/JSM.0b013e3181b8b52f
- Lak M et al. (2025). Does creatine cause hair loss? A 12-week randomized controlled trial. Journal of the International Society of Sports Nutrition, 22(sup1), 2495229. doi:10.1080/15502783.2025.2495229
- Xu C et al. (2024). The effects of creatine supplementation on cognitive function in adults: a systematic review and meta-analysis. Frontiers in Nutrition, 11, 1424972. doi:10.3389/fnut.2024.1424972
Food supplements do not replace a varied, balanced diet or a healthy lifestyle. Ask a healthcare professional for advice if you are taking medication, pregnant or breastfeeding.
