Does Creatine Cause Bloating, Diarrhoea or Stomach Problems?

Sometimes, and the serving size decides it. In 59 footballers a single 10 g (grams) serving doubled diarrhoea against the same amount split in two (55.6% versus 28.6%), while 5 g at a time matched placebo.¹ The first week's weight is water inside muscle, not gut bloating. Split the dose, take it with a meal, dissolve it fully.

Sources checked on 5 November 2026.

Does creatine make you bloated?

The gut side was tested in 59 male footballers over 28 days, taking 5 g twice a day, 10 g once a day, or placebo.¹ Across all three groups the commonest complaints were diarrhoea (39.0%), stomach upset (23.8%) and belching (16.9%), and 35% of the placebo group reported diarrhoea too, so a loose stool in a training week is not always the creatine. The 5 g twice a day group was no different from placebo.

A creatine loading phase means about 20 g a day for about a week, and the week readers say they "looked pregnant" is four large servings a day. Loading is optional: 3 g a day fills the same muscle stores in about 28 days,² and what creatine does depends on the store being full, not on how fast it filled.

Is it gut bloating or water in your muscles?

If the change is on the scale rather than in your stomach, it is water inside muscle. In 32 resistance-trained men and women who loaded for a week and then took 5 g a day for three weeks, muscle creatine, body mass and total body water all rose, but the split between water inside cells and water outside them did not change.³ In 27 resistance-trained men over eight weeks, water inside cells rose in step with muscle mass and the ratio of the two stayed the same.⁴ The sports-nutrition position stand describes short-term fluid retention of "about 0.5-1.0 L".⁵

So "why does my stomach look bigger on creatine?" has two answers. We found no creatine trial that measured waist size or gut distension; what they measured is where the water goes: into muscle cells, not under the skin or into the gut. A tight, windy stomach after a dose is the serving; a softer-looking middle on a heavier body is the scale being read as fat. The puffy-face question and the week-by-week scale belong to does creatine make you gain weight.

Can creatine cause diarrhoea, constipation or wind?

Diarrhoea tracks the serving size rather than the daily total. In the footballers, 10 g in one go doubled it; 5 g twice a day did not differ from placebo.¹ In a longer trial, 175 adults with motor neurone disease took 10 g a day or placebo for an average of 310 days: diarrhoea was reported by 35% on creatine and 24% on placebo, not a statistically significant difference.⁶ Three of the creatine group stopped, two for severe diarrhoea and one for severe nausea, and their symptoms subsided once they did.

Constipation was not reported as an outcome in these trials: there is no evidence that creatine causes it and none that it helps it.

Wind. Belching ran at 16.9% across all groups in the footballers, including placebo.¹ Flatulence, stool colour and blood in the stool were not recorded in these trials; the NHS advice on blood is below.

Can creatine make you feel sick or give you stomach pain?

Nausea is as common on placebo as on creatine. In the 310-day trial, 23% of the creatine group and 24% of the placebo group reported it, and general stomach discomfort ran at 19% against 18%.⁶ In the footballers, stomach upset was reported by 23.8% across all arms.¹ Stomach cramps were not reported separately in either. At the everyday dose, in 123 adults taking 5 g a day for six weeks each on creatine and placebo, 17% reported a side effect on creatine against 4% on placebo (risk ratio 4.25), digestion problems the commonest at 6% against 2%; 5 g is not symptom-free for everyone.⁷ Acid reflux and ulcers were not measured in these trials.

Why does creatine upset some stomachs?

Serving size is the tested cause, as the footballers' trial showed.¹ A large amount of slowly dissolving solid draws water into the gut, hence loose stools. Loading multiplies that by four. Undissolved powder is the untested cause: readers warn it must be "fully dissolved or you will be dealing with bloating and gas pains", and no trial has compared a fully dissolved drink with a gritty one.

Can you take creatine on an empty stomach?

No trial has compared an empty stomach with a fed one for symptoms. In 17 men given 2 g of creatine as a drink, in a protein bar or in a beta-glucan bar, food slowed absorption fourfold and eightfold, the same amount reached red blood cells by all three routes, and no side effects were reported.⁸ A meal slows creatine down without losing any, so if a dose on waking upsets you, take it with breakfast.

How long does creatine bloating last?

No trial has timed a stomach symptom from creatine. What the trials show: at 5 g twice a day, symptoms matched placebo across 28 days;¹ at 10 g a day for 310 days, nausea, discomfort and diarrhoea did not differ from placebo at any time point.⁶ Symptoms that continue at 5 g a day with a meal are worth taking seriously.

The NHS bloating page says to see a GP if you feel bloated regularly or have bloating with blood in your poo, and to ask for an urgent GP appointment or call 111 for bloating with a stomach ache or with vomiting.⁹ The NHS adds that bloating which does not go away can be a sign of something more serious such as ovarian cancer, whose symptom list starts with feeling bloated "roughly 12 or more times a month"; in UK GP records about one woman in 200 who consulted with bloating was diagnosed with ovarian cancer within a year (0.54%), so persistent bloating is a GP visit, and usually not cancer.^{9, 12, 13} The general causes of bloating, and why tests often come back normal, are on what causes bloating. Tell the GP you take creatine, because it changes the kidney blood-test reading; creatine vs creatinine gives the words to use. The water is on a separate clock: it stays while you keep taking creatine and leaves over about a month if you stop.²

How do you take creatine without an upset stomach?

1. Keep every serving at 5 g or less and split anything larger across the day.¹ If 5 g still bothers you, two servings of 2.5 g; how much creatine should you take covers 3 g against 5 g.
2. Take it with a meal. Food slows absorption without losing any of the dose, and the fed-stomach study reported no side effects.⁸
3. Dissolve it fully in a full glass, drink it straight away and swill the last mouthful; can you put creatine in coffee or tea covers hot drinks.
4. Do not load unless you have a date to hit. A 3 g daily dose fills muscle stores in about 28 days.² That is the amount behind the authorised wording, "Creatine increases physical performance in successive bursts of short-term, high intensity exercise", which applies at a daily intake of 3 g for adults doing high-intensity exercise. Drink as you normally would; the NHS guide is 6 to 8 cups or glasses of fluid a day, more in heat or during long sessions.¹⁰

Powder, capsules, tablets, gummies and drinks each deliver the amount on their label; we found no trial comparing formats, or any creatine salt with monohydrate, for stomach symptoms, so serving size and the meal are the levers. The reviews found no increase in dehydration or cramps on creatine;⁵ does creatine dehydrate you covers the water side.

What we don't know

Bloating, wind and waist size were not scored as outcomes in the trials we found; the serving-size finding rests on one 28-day survey of 59 footballers.¹ The one fed-state study measured absorption, not symptoms, so taking it with a meal is reasoned from it, not tested.⁸

Frequently asked questions

How do you get rid of creatine bloating?

If it is a gassy stomach: keep servings to 5 g, take them with a meal and dissolve the powder fully.^{1, 8} If it is the weight, it is water inside muscle, and it leaves within about a month if you stop.²

Does creatine make women bloated?

No trial has scored bloating as an outcome in women. Across 29 studies that monitored 951 women, gut side effects matched placebo (risk ratio 1.09), and the water is the same half a litre to a litre inside muscle.^{5, 11} The serving-size rule above applies.

What is the biggest side effect of creatine?

The water, about half a litre to a litre inside muscle, affects most people;⁵ stomach upset from large single servings is the unpleasant one, and splitting the dose brought it back to placebo rates.¹ Kidneys, liver, hair and cramps are weighed on creatine side effects.

Can I take creatine with IBS?

Not studied: no creatine trial has recruited people with IBS. The same steps apply; anyone with diagnosed IBS should run a new supplement past their GP or dietitian first.

Is creatine good or bad for gut health?

Not measured: no creatine trial has looked at the gut microbiome or any gut-health marker.

Sources

1. Ostojic SM, Ahmetovic Z. Gastrointestinal distress after creatine supplementation in athletes. Research in Sports Medicine, 2008. Randomised double-blind trial, 59 male footballers, 28 days; funding not stated on PubMed. PubMed 18373286.
2. Hultman E, et al. Muscle creatine loading in men. Journal of Applied Physiology, 1996. Supplementation study, 31 men; funding not stated on PubMed. PubMed 8828669.
3. Powers ME, et al. Creatine supplementation increases total body water without altering fluid distribution. Journal of Athletic Training, 2003. Randomised, 32 trained men and women, 28 days; funding not stated on PubMed. PubMed 12937471.
4. Ribeiro AS, et al. Creatine supplementation does not influence the ratio between intracellular water and skeletal muscle mass in resistance-trained men. International Journal of Sport Nutrition and Exercise Metabolism, 2020. Randomised, 27 resistance-trained men, 8 weeks; funding not stated on PubMed. PubMed 32916658.
5. Kreider RB, et al. International Society of Sports Nutrition position stand. Journal of the International Society of Sports Nutrition, 2017. Position stand; the society is sponsored by supplement companies. PubMed 28615996.
6. Groeneveld GJ, et al. Few adverse effects of long-term creatine supplementation in a placebo-controlled trial. International Journal of Sports Medicine, 2005. Randomised trial, 175 adults with motor neurone disease, 10 g a day for about 310 days; funding not stated on PubMed. PubMed 15795816.
7. Sandkühler JF, et al. The effects of creatine supplementation on cognitive performance. BMC Medicine, 2023. Randomised crossover, 123 adults, 5 g a day for 6 weeks each; authors declare no competing interests. PubMed 37968687.
8. Deldicque L, et al. Kinetics of creatine ingested as a food ingredient. European Journal of Applied Physiology, 2008. Crossover, 17 men, 2 g doses; funding not stated on PubMed. PubMed 17851680.
9. NHS. Bloating. Reviewed 21 January 2026. Read 30 October 2026. nhs.uk.
10. NHS. Water, drinks and hydration. Reviewed 17 May 2023. Read 30 October 2026. nhs.uk.
11. de Guingand DL, et al. Risk of adverse outcomes in females taking oral creatine monohydrate. Nutrients, 2020. Pooled analysis, 29 studies, 951 women; authors declare no conflicts. PubMed 32549301.
12. NHS. Ovarian cancer: symptoms. Reviewed 17 November 2025. Read 5 November 2026. nhs.uk.
13. Herbert A, et al. Predictive values for different cancers and inflammatory bowel disease of 6 common abdominal symptoms among more than 1.9 million primary care patients in the UK: a cohort study. PLoS Medicine, 2021. Primary-care cohort, UK GP records 2000 to 2017, 100,856 patients consulting with bloating or distension among more than 1.9 million; the 0.54% figure is from the full text; funded by the Medical Research Council and Cancer Research UK, no competing interests declared. PubMed 34339405.

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General information, not medical advice. If you have a medical condition or take regular medication, check with your GP or pharmacist first.