"Pros and cons of creatine" is searched about 9,000 times a month in the US across its variants, about a fifth of them asking specifically about women. Most answers are two bullet lists of equal weight. They should not be: some items on each side rest on dozens of trials, some on one, and three of the best-known "cons" rest on studies that never measured the thing they are cited for.
This page is a ledger. Each claim gets the evidence behind it, the size of the effect where one was measured, and a link to the page on this site that reads that evidence in full. It does not say whether anyone should take creatine.
The ledger
| Claim | Pro or con | Evidence | Size where measured | Read in full |
|---|---|---|---|---|
| More lean mass with resistance training | Pro | Strong — meta-analyses of randomised trials | +1.14 kg v training alone (12 RCTs, adults under 50) | Gain weight |
| More strength and power in short, hard efforts | Pro | Strong — position stands, AIS Group A | Varies by test; consistent direction | Benefits |
| Muscle in older adults and postmenopausal women | Pro | Moderate — smaller meta-analyses | +0.37 kg lean mass, +7.5 kg leg press (7 RCTs, 608 women) | For women |
| Brain, memory, sleep deprivation | Pro | Weak to mixed — EFSA refused a cognition claim in 2024 | Seen at 20 g/day short-term, not at 5 g/day | Brain claims |
| Water weight and scale gain | Con | Real — biopsy and body-water studies | About 1–2 kg in trials, mostly water | Gain weight |
| Stomach upset, diarrhoea | Con | Real, dose-dependent | 55.6% v 28.6% (one 10 g dose v two 5 g) | Side effects |
| Higher creatinine on a blood test | Con | Real — a lab artefact, not kidney damage | Small rise in serum creatinine; measured filtration unchanged | Bloodwork |
| Hair loss | "Con" | Not shown — the source never measured hair | No difference in hair (2025 RCT) | Hair loss |
| Kidney damage in healthy people | "Con" | Not shown in trials measuring filtration directly | No change in ⁵¹Cr-EDTA clearance | Kidneys |
| "It's a steroid" | "Con" | False — creatine is an amino-acid derivative | — | Is creatine a steroid |
| Cost | Con | Measured | $0.03–$0.12 a gram for plain powder; gummies to $0.74 | Cost |
"Strong" means repeated randomised trials pooled in meta-analyses with consistent results; "moderate" means pooled trials with wider uncertainty or a narrower population; "weak to mixed" means small trials, inconsistent results, or a regulator declining the claim. The grades are this site's reading, and the evidence behind each is linked.
The pros, and what they rest on
Lean mass and strength. A 2024 meta-analysis of 12 randomised trials in adults under 50 found creatine added to resistance training increased lean body mass by 1.14 kg (95% CI 0.69 to 1.59) more than training alone, with 0.88 percentage points less body fat (Desai et al., J Strength Cond Res 2024, PMID 39074168). A 2023 meta-analysis restricted to direct imaging of muscle size found a much smaller effect, 0.10 to 0.16 cm of muscle thickness (Burke et al., Nutrients 2023, PMID 37432300) — part of the lean-mass gain is water inside the muscle. Both findings are about creatine with training; without training the effect is small or absent in most trials.
Who classifies it. The Australian Institute of Sport puts creatine monohydrate in Group A of its supplement framework, its strongest evidence tier, for specific uses in sport. The International Society of Sports Nutrition's 2017 position stand restates its earlier conclusion that creatine monohydrate is "the most effective ergogenic nutritional supplement currently available to athletes" for increasing high-intensity exercise capacity and lean body mass during training (Kreider et al., J Int Soc Sports Nutr 2017, PMID 28615996); several of its authors disclose ties to the supplement industry, set out on creatine benefits.
The brain. This is the weakest of the pros. In November 2024 the European Food Safety Authority's nutrition panel assessed a cognition claim submitted by a creatine manufacturer and concluded that a cause-and-effect relationship had not been established; the working-memory effects appeared at 20 g a day for five to seven days and not at 5 g a day. The trials are read on creatine and the brain and, for the most-cited situation, creatine and sleep.
The cons that are real
Water weight. Creatine is stored in muscle with water, and a loading week raises muscle creatine by about a fifth. In a 2000 trial of 23 weight-trained men, body mass on creatine rose from 86.7 to 88.7 kg over six weeks with no change in fat mass (Becque et al., PMID 10731009). For someone in a weight-class sport, or anyone reading the scale daily, that is a real effect. The numbers are on does creatine make you gain weight and creatine bloating.
Stomach upset at large single doses. Across the 2025 analysis of 685 trials, gastrointestinal complaints appeared in 9.2% of creatine study groups against 4.3% of placebo groups, although the difference did not hold when counted across individual participants (Antonio, Kreider et al., J Int Soc Sports Nutr 2025, PMID 40198156). The dose pattern comes from a 28-day trial of 59 soccer players: diarrhoea was reported by 55.6% of those taking 10 g in one dose against 28.6% of those taking two 5 g doses, and the split-dose group did not differ from placebo (Ostojic & Ahmetovic, Res Sports Med 2008, PMID 18373286). The full side-effect census is on creatine side effects.
A blood test that reads worse than the kidneys are. Creatine is broken down to creatinine, the marker laboratories use to estimate kidney filtration. Supplementing raises serum creatinine, so the estimate (eGFR) reads lower, while filtration measured directly does not change. That matters for anyone whose kidneys are monitored or whose medicines are dosed by eGFR. Explained on what creatine does to a blood test.
Cost. Small for plain powder, $0.03 to $0.12 a gram on brands' own stores in October 2026, or $4.50 to $18 a month at 5 g a day; four to ten times that in single-serve sticks and gummies (cost per gram).
The cons that are myths
Hair loss. The claim traces to one 2009 study of 20 rugby players that measured dihydrotestosterone (DHT), which rose 56% during loading; it did not measure hair (van der Merwe et al., PMID 19741313). The first trial to measure hair directly, in 2025, randomised 45 trained men to 5 g a day or placebo for 12 weeks and found no difference in hair density, follicle count or DHT (Lak et al., PMID 40265319). Details on creatine and hair loss.
Kidney damage in healthy people. Two randomised trials measured filtration directly by chromium-51 EDTA clearance — in postmenopausal women and in people with type 2 diabetes — and found no change after 12 weeks. In the longest creatine trial, 1,741 people with Parkinson disease on 10 g a day for up to eight years, serious renal events were no more common on creatine than placebo. The census is on creatine and kidneys and is creatine bad for you. None of this covers people who already have kidney disease.
"Creatine is a steroid." It is a compound made from three amino acids, produced by the body and eaten in meat and fish. It is not a hormone, and it is not on the WADA prohibited list (is creatine a steroid).
For women
The molecule is the same; the evidence base is thinner. Of 417 randomised creatine trials indexed on PubMed on 11 September 2026, 37 were female-only and 202 male-only, and the loading protocol on most tubs was worked out in 48 men. The best current evidence in women, a 2026 meta-analysis of seven trials and 608 postmenopausal women, found lean mass up 0.37 kg and leg-press strength up 7.5 kg where creatine of at least 5 g a day was combined with resistance training, with a prediction interval for lean mass that crosses zero. Those figures and their limits are on creatine for women; pregnancy and breastfeeding, where almost nothing has been studied, have their own pages (pregnancy, breastfeeding).
Who should ask a clinician first
Anyone with kidney disease or reduced kidney function; anyone whose medicines are dosed by kidney blood tests; anyone on an antidepressant or mood stabiliser, a diabetes medicine, a statin, a blood thinner or a diuretic (the trials and gaps are on creatine and medications); anyone with diabetes (creatine and diabetes); and anyone pregnant or breastfeeding.
Sources and dates
- Desai I et al. The effect of creatine supplementation on resistance training-based changes to body composition. J Strength Cond Res 2024;38(10):1813–21. PMID 39074168.
- Burke R et al. The effects of creatine supplementation combined with resistance training on regional measures of muscle hypertrophy. Nutrients 2023;15(9):2116. PMID 37432300.
- Antonio J, Kreider RB et al. Analysis of reported side effects across 685 human creatine trials. J Int Soc Sports Nutr 2025. PMID 40198156 (figures as read and dated on creatine side effects).
- Ostojic SM, Ahmetovic Z. Gastrointestinal distress after creatine supplementation in athletes: are side effects dose dependent? Res Sports Med 2008;16(1):15–22. PMID 18373286, abstract read 2026-11-03.
- Becque MD, Lochmann JD, Melrose DR. Med Sci Sports Exerc 2000;32(3):654–8. PMID 10731009.
- van der Merwe J, Brooks NE, Myburgh KH. Clin J Sport Med 2009;19(5):399–404. PMID 19741313.
- Lak M et al. J Int Soc Sports Nutr 2025;22(sup1):2495229. PMID 40265319.
- Kreider RB 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. PMID 28615996, full text read 2026-11-03.
- Australian Institute of Sport, Sports Supplement Framework, Group A creatine entry (as cited and dated on how long creatine takes to work).
- EFSA NDA Panel opinion on creatine and cognitive function, November 2024 (as read and dated on creatine benefits).
- Female/male trial census and the 2026 postmenopausal meta-analysis, PMID 42141930, as counted and dated on creatine for women.
- Figures carried from this site's linked pages keep the dates given on those pages.