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.

Does creatine make you bloated?

Readers ask "is it my stomach or water?", and the trials measured both: gut complaints in the hours after a dose, and body water over the first fortnight.

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 automatically the creatine. The 5 g twice a day group was no different from placebo; the group taking 10 g at once reported diarrhoea at 55.6%, double the split-dose rate.

That is the loading connection. A creatine loading phase means about 20 g a day for five to seven days, 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. No creatine trial has measured waist size or gut distension; what they measured is where the water goes, and it 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 water, the puffy-face question and what the scale does week by week 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. On a GLP-1 medicine, nausea, constipation and diarrhoea are common effects of the medicine itself: read GLP-1 side effects before blaming either.

Constipation has never been measured as an outcome in a creatine trial: 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 and stool colour were not recorded in any trial. Blood in the stool has never appeared in a creatine trial; the NHS advice on it 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 Cramps ("doubled over with stomach cramps" at 20 g a day, in one reader's words) were not scored separately in either trial. At the everyday dose, in 123 adults taking 5 g a day for six weeks each on creatine and placebo, side effects were reported 4.25 times more often on creatine, though the report does not name them; 5 g is not symptom-free for everyone.⁷ Acid reflux and stomach ulcers have not been measured in any creatine trial.

Why does creatine upset some stomachs?

Serving size is the tested cause: the footballers' trial compared the same daily amount as one serving and as two, and the single serving doubled diarrhoea.¹ The usual explanation is that a large amount of a slowly dissolving solid draws water into the gut while it is absorbed, which is why the symptom is 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; dissolving creatine fully is covered on the coffee page.

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, so any number you have read is a guess. 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 unusual, and 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 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; no trial has compared 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.

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

Can creatine cause nausea?

Not more than placebo in the longest trial: 23% on 10 g a day reported nausea over 310 days, against 24% on placebo.⁶

What is the biggest side effect of creatine?

By how many people it affects, the water: about half a litre to a litre inside muscle in the first weeks.⁵ By how unpleasant it is, stomach upset from large single servings, which splitting the dose removes.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 or measured IBS symptoms. The same steps apply, and 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 marker of gut health in either direction.

Sources

1. Ostojic SM, Ahmetovic Z. Gastrointestinal distress after creatine supplementation in athletes: are side effects dose dependent? Research in Sports Medicine, 2008. PubMed 18373286.
2. Hultman E, Söderlund K, Timmons JA, Cederblad G, Greenhaff PL. Muscle creatine loading in men. Journal of Applied Physiology, 1996. PubMed 8828669.
3. Powers ME, et al. Creatine supplementation increases total body water without altering fluid distribution. Journal of Athletic Training, 2003. 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. PubMed 32916658.
5. Kreider RB, et al. 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, 2017. 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. PubMed 15795816.
7. Sandkühler JF, et al. The effects of creatine supplementation on cognitive performance: a randomised controlled study. BMC Medicine, 2023. PubMed 37968687.
8. Deldicque L, et al. Kinetics of creatine ingested as a food ingredient. European Journal of Applied Physiology, 2008. PubMed 17851680.
9. NHS. Bloating. Page last reviewed 21 January 2026; fetched 11 October 2026. https://www.nhs.uk/conditions/bloating/
10. NHS. Water, drinks and hydration. Page last reviewed 17 May 2023; fetched 11 October 2026. https://www.nhs.uk/live-well/eat-well/food-guidelines-and-food-labels/water-drinks-nutrition/

This article is general information, not medical advice. If you have a medical condition or take regular medication, check with your GP or pharmacist before starting creatine.