Diarrhea on Ozempic, Wegovy or Zepbound: What to Eat and Drink

Diarrhea is one of the most common side effects of semaglutide (Ozempic, Wegovy) and tirzepatide (Zepbound, Mounjaro): it shows up in the table of common adverse reactions on all four US labels^[1,2,3,4]. It’s usually mild, clusters around dose increases, and each episode tends to last a few days^[1,2,7]. What helps is replacing fluids and salts, eating small, bland meals, and for a few days avoiding what makes it worse: fat, alcohol, caffeine, fruit juice, soda and “sugar-free” sweets^[13,14,16]. Call your prescriber if it lasts more than 2 days, or if you see blood, have a high fever or notice signs of dehydration^[11].

I built this guide from the US prescribing information and Medication Guides for Wegovy, Zepbound, Ozempic and Mounjaro, the 2025 joint advisory on nutrition and GLP-1 therapy from four US medical and nutrition societies, a consensus of Spanish experts on digestive side effects, and the diarrhea pages of the NIDDK (part of the US National Institutes of Health), MedlinePlus and the UK’s NHS. Where the US labels don’t report a figure, I use the EU prescribing information and say so. On names: Ozempic and Mounjaro are the type 2 diabetes versions of semaglutide and tirzepatide; Wegovy and Zepbound are the same molecules approved for weight management. The full eating plan is in my guide to what to eat on GLP-1 medications.

How common diarrhea is, according to the labels

These are the figures each US label reports^[1,2,3,4]. The Wegovy and Zepbound rows come from weight-management trials; Ozempic and Mounjaro, from trials in adults with type 2 diabetes.

Every figure in the table comes from the US labels except the one I mark as EU. The EU prescribing information reports somewhat different percentages, because it rounds and pools the trials differently^[5,6]. Four things to keep in mind:

• It’s short-lived. In the analysis of the STEP 1 to 3 trials, each episode lasted a median of 3 days, similar to placebo^[7]. The EU prescribing information for Wegovy gives the same median; the US label doesn’t report durations^[1,5].
• It’s usually mild. The US labels count the severe digestive side effects of any kind: 4.1% on Wegovy injection versus 0.9% on placebo, and 1.7%, 2.5% and 3.1% on Zepbound 5, 10 and 15 mg versus 1% on placebo^[1,2]. In the tirzepatide weight-management trial described in the EU prescribing information for Mounjaro, digestive side effects were mild in 60.8% of cases and moderate in 34.6%^[6]. On Wegovy, 0.7% stopped treatment because of diarrhea, versus 0.1% on placebo^[1].
• People on placebo get it too. About 16 in 100 did in the Wegovy trials^[1]. The STEP analysis authors attribute part of that to digestive problems already being more common in people with obesity^[7].
• These numbers don’t compare the drugs. They come from different trials, and the US labels themselves warn that rates from one drug’s trials can’t be directly compared with another’s^[1,2,3,4].

Why GLP-1 medications can cause diarrhea

The labels don’t explain the mechanism. The 2025 advisory links the slower stomach emptying to bloating and nausea, and diarrhea to something else: occasionally, GLP-1 medications affect how the intestine moves or what it secretes^[9]. The STEP analysis points to changes in how fast things move through the lower gut, while admitting the evidence is lacking^[7]. The Spanish consensus adds that long-acting GLP-1 medications cause less nausea but more diarrhea, perhaps because of a more sustained effect on the intestine^[10].

Some factors can add up:

• The dose. According to the 2025 advisory, higher doses are more likely to cause these symptoms^[9].
• Long-standing constipation. It can lead to reactive diarrhea, the same advisory warns^[9]. I cover it in constipation on GLP-1 medications.
• Metformin. The Spanish consensus says GLP-1 medications may make diarrhea worse in people taking metformin, especially together with omeprazole^[10]. The 2025 advisory, on the other hand, finds that the combination doesn’t appear to worsen digestive side effects in general^[9]. If this applies to you, bring it up with your doctor.
• Your kidneys. The EU prescribing information for Wegovy notes that people with moderate renal impairment may have more digestive side effects^[5], and the US label that the risk of kidney adverse reactions was higher in adults with a history of kidney impairment^[1].

And not every bout of diarrhea is the medication: the NHS points out that the most common causes are a stomach bug and food poisoning^[16].

What to eat when you have diarrhea

The NIDDK is clear: most experts don’t recommend fasting or a restricted diet beyond avoiding a few foods, and once you feel like eating again, you can usually go back to your normal diet^[13].

Tips from MedlinePlus, the NIDDK and the Spanish consensus:

• Small, frequent meals instead of 3 large ones, as MedlinePlus advises^[14]. If you also feel sick, see my guide to GLP-1 nausea and what to eat.
• Mild, low-fat dishes. Baked or broiled chicken, turkey, fish, beef or pork, cooked eggs, white rice, pasta, white bread, oatmeal and baked potatoes^[14].
• Cooked vegetables, without skins or seeds. MedlinePlus lists carrots, green beans, mushrooms, beets, asparagus tips, acorn squash and peeled zucchini^[14]; the Spanish consensus adds chicken broth and very ripe fruit without the skin^[10].
• Something salty and something with potassium. MedlinePlus suggests salty foods such as soup, and high-potassium foods such as bananas and potatoes^[14]. If you have significant kidney disease, check with your doctor first.
• Dairy, depending on how it sits. After acute diarrhea, some people have trouble digesting lactose for up to a month or more (NIDDK)^[13]. MedlinePlus suggests low-fat milk, cheese or yogurt, and cutting back on dairy for a few days if it makes the diarrhea worse or gives you gas^[14].

Soluble fiber: yes, but slowly

MedlinePlus explains that soluble fiber attracts water and turns into a gel that slows digestion. It’s in oat bran, barley, some fruits and vegetables, and psyllium, a common fiber supplement^[15]. Coarser, high-fiber foods are another story: the Spanish consensus advises cutting back for a few days on whole grains, beans and lentils, nuts, cabbage, cauliflower, onions and fruits such as apples, pears or plums, then bringing them back gradually as you improve^[10].

What about a fiber supplement? The 2025 advisory says that if diarrhea is significant, fiber capsules or powders add bulk to the stool^[9]. MedlinePlus says to ask your provider first, and that goes double if you take other medicines^[14].

What to avoid for a few days

The NIDDK notes that some liquid medicines also contain sugar alcohols^[13]. If you take syrups, ask your pharmacist.

10 gentle foods for these days

Foods from our database that fit these tips. I include protein, because when your appetite is small it helps if the little you eat brings some. Meat and fish are weighed raw; rice, oatmeal, potato and pumpkin, cooked.

Composition data: USDA FoodData Central^[18], as listed on each food page; potato values are for a potato boiled in its skin, and zucchini values are for raw zucchini. Servings are a guide, not a recommendation. More options in the filling foods finder, filtered to easy-to-digest foods.

A sample day

A rough example for a day with diarrhea and a small appetite, not a weight-loss menu. If you’re still hungry, add more rice, bread or potato, and once you feel better, go back to your usual way of eating.

Sip fluids between meals. Fiber stays below the 25 g a day that the European Food Safety Authority considers adequate for adults^[17]. That’s on purpose for these days; afterward, it’s worth building it back up gradually, and the fiber calculator can help.

Fluids and salts: what matters most

Diarrhea drains water and salts, and the labels take that seriously:

• All four US labels carry the same warning, “Acute Kidney Injury Due to Volume Depletion”: there have been postmarketing reports of acute kidney injury, in some cases requiring hemodialysis, and most occurred in patients whose nausea, vomiting or diarrhea led to dehydration^[1,2,3,4]. The labels ask prescribers to monitor kidney function in patients with those symptoms^[1,2,3,4].
• The Medication Guides put it plainly: diarrhea, nausea and vomiting may cause a loss of fluids (dehydration), which may cause kidney problems, and drinking fluids helps reduce your chance of dehydration^[1,2,3,4].
• Older adults. The EU prescribing information for Mounjaro adds a nuance the US labels don’t spell out: avoiding fluid depletion and electrolyte disturbances matters especially in older people, who may be more susceptible to these complications^[6].

What usually helps:

• Water and fluids with salts. The NIDDK mentions water, broths and oral rehydration solutions, which contain glucose and electrolytes (minerals such as sodium and potassium)^[12].
• A cup after every loose stool. MedlinePlus advises drinking at least 1 cup (240 ml, 8 fl oz) of liquid each time, and 8 to 10 glasses of clear fluids a day, with water as the best choice^[14].
• With diabetes, kidney disease or older age, ask first. The NIDDK asks older adults, people with a weak immune system and people with diabetes or kidney disease to talk with their doctor before drinking oral rehydration solutions^[12]: a specific solution or amount may work better.
• Sports drinks, with a question mark. The NIDDK includes them among the options^[12], but the Spanish consensus advises avoiding them^[10]. If you’re unsure, ask your pharmacist.

If you have to limit fluids because of heart or kidney disease, follow what your doctor has told you. The hydration calculator shows a general daily water reference, and there’s more detail in hydration on GLP-1 medications.

Dose increases and medicines for diarrhea

Treatment starts at a low dose that your prescriber raises in steps. The Zepbound label says most nausea, vomiting and diarrhea occurred during dose escalation and decreased over time^[2], and the Spanish consensus describes diarrhea starting in the first 4 weeks and dropping noticeably afterward^[10]. The US labels give prescribers room to adjust: the Wegovy label says that if a dose isn’t tolerated during escalation, prescribers can consider delaying the next increase for 4 weeks^[1], and the Zepbound label that if a maintenance dose isn’t tolerated, they can consider a lower one^[2]. That’s their call, not yours: don’t change your dose on your own. Jotting down which days you have diarrhea and how much you drink in the symptom diary gives you something concrete to bring to your appointment.

The 2025 advisory mentions that anti-diarrheal medicines can bring short-term relief^[9]. In the SURMOUNT-1 to -3 trials, 5.2% to 9.3% of people on tirzepatide used one, versus 1.2% to 2.2% on placebo, mostly in the first 24 weeks (Rubino analysis)^[8]. The NIDDK adds that doctors typically advise against over-the-counter anti-diarrheals if you have bloody stools or a fever, and that you should see a doctor if the diarrhea gets worse or lasts more than 2 days while you take them^[12]. As for probiotics, many doctors and professional societies don’t believe the evidence supports their use for diarrhea^[12]. Either way, ask your prescriber or pharmacist, and tell them you take semaglutide or tirzepatide.

When to call your doctor right away

The NIDDK adds that people who are pregnant, over 65, taking antibiotics or have a weakened immune system are more likely to have health problems from diarrhea and should keep in touch with their doctor^[11].

Frequently asked questions

How long does diarrhea last on Ozempic, Wegovy or Zepbound?

With Wegovy, each episode lasted a median of 3 days, according to the EU prescribing information and the STEP analysis^[5,7]. The US labels don’t give a duration, but they place most diarrhea in the dose-escalation period, and the Zepbound label says it decreased over time^[1,2].

Do I lose more weight if I have diarrhea?

There’s no evidence for that. In STEP 1 to 3, digestive side effects explained less than 1 percentage point of the weight loss attributable to semaglutide^[7]. In SURMOUNT, nausea, vomiting, diarrhea and indigestion were associated with, at most, 3.1% of total weight loss^[8].

Do I have to stop treatment?

That’s not a decision to make on your own: talk to your prescriber. If you also have heartburn or reflux, I cover it in acid reflux and heartburn on GLP-1 medications.