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How do I relieve constipation on Wegovy, Ozempic or Mounjaro?

GLP Guidebook teamUpdated 22 Oct 202614 sourcesWritten from published sources
What we checked14 sources, each one opened and linked to the sentence it supportsLast checked 22 Oct 2026 · Next review due 22 Oct 2027 · How we write
The short answer

Canadian health services advise more water, more fibre and regular exercise for constipation on Wegovy or Ozempic (semaglutide) or Mounjaro (tirzepatide). A pharmacist can advise on a laxative. In Canada’s Wegovy monograph, 24% on 2.4 mg had constipation, against 11% on placebo. A typical bout lasted 47 days.

Before you go further
  • GLP‑1 medicines are prescription drugs in Canada. Your prescriber decides your dose.
  • Side-effect rates come from Health Canada’s product monographs, named each time.
  • Laxatives are named by their generic names only. We don’t rank products.

How common is constipation on Wegovy, Ozempic and Mounjaro?

Canada’s Wegovy leaflet lists constipation as very common, affecting more than 1 in 10 people. The monograph says it lasts longer than other stomach effects.1

In three 68-week trials, 24% on Wegovy (semaglutide) 2.4 mg had it, against 11% on a placebo (dummy injection). The monograph calls it mild to moderate. A typical bout lasted 47 days, against 8 days for nausea.1 On Zepbound, the weight-loss brand of tirzepatide, it was 11% to 17% over 72 weeks, against 5%.4

At diabetes doses it was less common. It affected about 6% to 7% on Ozempic 0.5 or 1 mg, against 3% on comparators. On Mounjaro (tirzepatide) it was about 6%, against 1% on placebo.2,3 Emergency Care BC describes constipation as stools that are hard to pass or come less often than your normal.5 Other side effects are in Guide 5: side effects and risks.

What do Canadian health services say helps?

Emergency Care BC advises a high-fibre diet, lots of water and other fluids, and regular exercise.5

Its examples include fruit, vegetables, prunes or prune juice, oatmeal, bran cereal and whole-grain bread. If you’re bloated, it says to start with less fibre and build up slowly. It also says not to hold in the urge, and to rest your feet on a small step stool on the toilet.5 A Santé Québec sheet adds legumes, smaller meals and a 20-minute daily walk.6

Health Canada says women need 25 g of fibre a day and men 38 g; most Canadians get about half.7 A small US trial, not a GLP‑1 study, gave adults with long-term constipation 2 green kiwifruit or 100 g of prunes a day. Both eased straining over 4 weeks.8

Which laxative, and for how long?

Emergency Care BC lists polyethylene glycol, magnesium products, psyllium and lactulose as non-prescription laxatives. It says to ask a pharmacist or doctor which suits you.5

Health Canada’s labelling standards say bulk-forming laxatives work in 12 to 72 hours, with a full glass of water each dose. Oral stimulant laxatives work in 6 to 12 hours.10,11 The general standard says not to use a laxative with abdominal pain, nausea, fever or vomiting. It also says not to take any laxative for more than 1 week unless a doctor sets a schedule. Labels other than bulk-forming ones must also warn that overuse may cause dependence.9

Dose changes are your prescriber’s call. Canada’s Wegovy monograph says the slow dose steps reduce stomach symptoms. If a step isn’t tolerated, the prescriber can delay the next one by 4 weeks.1 The leaflets say not to stop without talking to your healthcare professional.1,4

When is constipation on a GLP‑1 serious?

Canada’s Wegovy, Ozempic and Mounjaro monographs list ileus, and Wegovy and Ozempic also list bowel obstruction, as reported after sale with unknown frequency.1,2,3

The Wegovy leaflet describes ileus as the gut being unable to push food and waste out. It can cause severe constipation with stomach ache, bloating or vomiting.1 Canada’s Zepbound leaflet lists ileus as a serious side effect, with bloating, belly pain, cramping, gas, nausea, vomiting or constipation. It says to stop and get medical help right away.4 To tell Health Canada about a side effect, see how to report one.

What do people on Wegovy, Ozempic or Mounjaro report about constipation?

From public patient forums: 10 Reddit threads in r/Zepbound, r/Wegovy, r/Semaglutide, r/Ozempic and r/MounjaroUK, read in October 2026. Personal reports, not medical evidence.

What people describe

  • Matches the label Several say it began after a dose increase, sometimes months in. Canada’s Wegovy monograph says the slow dose steps lower the chance of stomach symptoms.1
  • Matches Emergency Care BC Several describe stool so hard it got stuck, and a few needed emergency care. Emergency Care BC says to go to an emergency department if you can’t pass any stool for several days.5
  • Matches the Canadian label Several say the anti-nausea medicine ondansetron made it worse. Canada’s ondansetron monograph names constipation, in 4% of trial patients, among its most frequent side effects.12
  • Not studied A few say eating very little leaves less to pass, so fewer bowel movements can be normal. We found no Canadian source on this for people on GLP‑1 medicines.

Advice people share

  • Matches Emergency Care BC and a trial Most start with more water and fibre, and many eat prunes or kiwifruit daily. Emergency Care BC advises fluids, fibre built up slowly and prunes. A small US trial, not of GLP‑1 users, found kiwifruit and prunes eased straining.5,8
  • Matches Santé Québec Most replies in threads about blockages say not to let it run past a few days. A Santé Québec sheet says to seek professional help if you’ve been constipated for several days.6
  • Health Canada says otherwise Many take a laxative every day for weeks or months, often polyethylene glycol or magnesium, and some use senna. Health Canada’s labelling standard says not to take any laxative for more than 1 week unless a doctor has set a schedule.9
  • Label says otherwise A few skip or put off GLP‑1 doses on their own. Canada’s leaflets say not to stop without talking to your healthcare professional, and the Wegovy monograph leaves delaying a dose step to the prescriber.1,4
Get help now: call 9-1-1 or go to the nearest emergency department for severe belly pain or pressure, severe or persistent vomiting, or black blood in your stool.13,6 Emergency Care BC also says to go to an emergency department or urgent care centre if you’re constipated and:5
  • there’s blood in the toilet or on the toilet paper
  • your stool is dark black or looks like tar
  • you have a fever over 38 °C
  • you have intense or worsening belly or rectal pain
  • you’re vomiting
  • you can’t pass any stool for several days
  • you feel weak or dizzy

Call your pharmacist or clinic if you’ve been constipated for several days, can’t pass gas, or have pain in your belly or bottom.6 Canada’s Zepbound leaflet says to stop it and get medical help right away for signs of ileus.4 For advice that isn’t an emergency, most provinces have a nurse line on 8-1-1 (Info-Santé 811 in Quebec).14

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Related questions

How do I report a side effect in Canada? Why am I not losing weight on Wegovy, Ozempic or Mounjaro? Is Apo-Semaglutide the same as Ozempic? Do I need to stop Ozempic before surgery in Canada?
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Sources

  1. Novo Nordisk Canada. Wegovy (semaglutide injection) Product Monograph, Date of Authorization 2 October 2026 (4.2 dose escalation “to reduce the likelihood of gastrointestinal symptoms”, “consider delaying dose escalation for 4 weeks”; 7 “severe gastrointestinal disease (intestinal obstruction and ileus)”, post-marketing, unknown frequency; adverse reactions: constipation 24% vs 11% (STEP 1–3, 68 weeks), “mild to moderate in severity and were of longer duration”, median duration 47 days vs nausea 8 days; Patient Medication Information: constipation “very common”, ileus and bowel obstruction “unknown”, “Do not stop using this medicine without talking to your healthcare professional”). Health Canada Drug Product Database. pdf.hres.ca (PDF)
  2. Novo Nordisk Canada. Ozempic (semaglutide injection) Product Monograph, Date of Authorization 13 July 2026 (7 “severe gastrointestinal disease (ileus)”; intestinal obstruction and ileus reported post-marketing “with an unknown frequency”; Table 2, type 2 diabetes: constipation 6.9% on 0.5 mg and 6.2% on 1 mg vs 2.7% on comparator). Health Canada Drug Product Database. pdf.hres.ca (PDF)
  3. Eli Lilly Canada. Mounjaro (tirzepatide injection) Product Monograph, Date of Authorization 23 June 2026 (Table 2, type 2 diabetes, placebo-controlled trials: constipation 5.9%, 5.8% and 6.6% on 5, 10 and 15 mg vs 1.3% on placebo; 8.5 post-market adverse reactions: “Gastrointestinal disorders: ileus”, frequency not reliably estimable). Health Canada Drug Product Database. pdf.hres.ca (PDF)
  4. Eli Lilly Canada. Zepbound (tirzepatide injection) Product Monograph, Date of Authorization 11 June 2026 (Table 2, SURMOUNT-1 and -2, 72 weeks: constipation 16.8%, 14.1% and 10.8% on 5, 10 and 15 mg vs 5.2% on placebo; Patient Medication Information: ileus “bloating, abdominal pain and cramping, gas, nausea, vomiting, constipation, loss of appetite”, stop using and get immediate medical help; “Do not change your dose or stop using ZEPBOUND without talking to your healthcare professional”). Health Canada Drug Product Database. pdf.hres.ca (PDF)
  5. Emergency Care BC (Provincial Health Services Authority). Constipation: patient discharge sheet. Last reviewed 4 June 2024 (when to get help; fibre, fluids, step stool; non-prescription laxatives). Opened 22 Oct 2026. emergencycarebc.ca (PDF)
  6. Santé Québec, Santé Montérégie. Constipation health sheet (English), November 2025 (“EMERGENCY: CALL 911 IF There is black blood in your stool”; “When to seek professional help: You have been constipated for several days”, “You are unable to pass gas”, “You have pain in your belly or anus”; legumes, smaller meals, walk 20 minutes a day). Opened 22 Oct 2026. santemonteregie.qc.ca (PDF)
  7. Health Canada. Fibre (“Canadian women need 25 grams of fibre per day and men need 38 grams”; “Most Canadians are only getting about half that much”). Page dated 11 July 2025. Opened 22 Oct 2026. canada.ca
  8. Chey SW, Chey WD, Jackson K, Eswaran S. Exploratory comparative effectiveness trial of green kiwifruit, psyllium, or prunes in US patients with chronic constipation. Am J Gastroenterol 2021;116(6):1304–1312. DOI 10.14309/ajg.0000000000001149. PMID 34074830. 79 adults, 4 weeks; not a GLP‑1 study. PubMed
  9. Health Canada. Laxatives: General, labelling standard for non-prescription drugs (“Do not use in the presence of abdominal pain, nausea, fever or vomiting”; “not to take any type of laxative for more than one (1) week” unless a physician has ordered a special schedule; “overuse or extended use may cause dependence for bowel function”). Opened 22 Oct 2026. canada.ca
  10. Health Canada. Laxatives: Bulk Forming, labelling standard for non-prescription drugs, adopted 9 July 2012 (“Drink a full glass (250 mL or 8 ounces) of water with each dose”; “Produces bowel movement in 12 to 72 hours”). Opened 22 Oct 2026. canada.ca
  11. Health Canada. Laxatives: Stimulant, labelling standard for non-prescription drugs (“Oral products produce action in 6 to 12 hours”). Opened 22 Oct 2026. canada.ca
  12. Novartis Pharmaceuticals Canada. Zofran and Zofran ODT (ondansetron) Product Monograph, Date of Revision 9 November 2021 (“The most frequent adverse events reported in controlled clinical trials were headache (11%) and constipation (4%)”). Health Canada Drug Product Database. pdf.hres.ca (PDF)
  13. MedlinePlus (US National Library of Medicine). Recognizing medical emergencies (US page: warning signs of a medical emergency from the American College of Emergency Physicians, including severe abdominal pain or pressure and severe or persistent vomiting; call 911 or the local emergency number). Reviewed 8 January 2025. Opened 22 October 2026. medlineplus.gov
  14. Heart and Stroke Foundation of Canada. Medical services by phone (811 health lines by province and territory, including Info-Santé 811 in Quebec). Checked 22 October 2026. heartandstroke.ca

Last checked 22 Oct 2026 · Next review due 22 Oct 2027 · Report an error

How this answer was made. Written by the GLP Guidebook team from the sources above, all checked on 22 Oct 2026. Percentages are rounded from the monograph tables. The ‘What people report’ section summarizes public patient forum posts we read; it is not medical evidence, and we never pass on advice that goes against the label. It’s general information, not medical advice, and not an advertisement for any medicine. Talk to a doctor, nurse practitioner or pharmacist before starting, stopping or changing any medicine. How we write