In short
On the U.S. labels, constipation affected up to 24% of people, against up to 11% on placebo. One expert consensus reports a median of 47 days in people with obesity. Fluids, gradually adding fiber and moving more are the usual first steps. Ask before starting a laxative or supplement.
Get the free food guide for bad daysWhat expert groups suggest for nausea, no appetite, constipation, diarrhea and heartburn.
How common it is
| Label | Constipation | On placebo |
|---|---|---|
| Ozempic (0.5, 1 mg) | 5%, 3.1% | 1.5% |
| Mounjaro (5, 10, 15 mg) | 6%, 6%, 7% | 1% |
| Wegovy (2.4 mg) | 24% | 11% |
| Zepbound (5, 10, 15 mg) | 17%, 14%, 11% | 5% |
Share of people in the labels' placebo-controlled trials. Ozempic and Mounjaro figures are from people with type 2 diabetes, and Zepbound and Wegovy from people with obesity or overweight, so the rows are not a comparison between medicines.
When it happens
One expert consensus says it can start in the first 16 weeks, particularly the first 28 days, and lasts longer than other stomach side effects, with a median of 47 days in people with obesity.
What experts suggest
These come from expert groups rather than trials.
- Drink more water or sugar-free liquids.
- Add fiber gradually, for example prunes, and eat water-rich fruit and vegetables.
- Move more, if you can.
The same advisory notes that high-protein or high-fat foods can make constipation worse, and also asks people to keep protein up. If the two pull against each other, ask a dietitian or your prescriber.
The daily fiber goal and water estimate give you a starting point, and what to eat on a GLP-1 has more on food. See the side effects guide for other symptoms.
What to ask your prescriber
Magnesium, fiber supplements, polyethylene glycol and stool softeners are mentioned by expert groups. Ask before you start one, especially if you have other conditions or take other medicines.
All four labels also list reports after approval of ileus, intestinal obstruction and severe constipation. Tell your provider about severe constipation, or stomach pain with swelling.
When to get help
The labels and Medication Guides name these. This is not the full list, so read the guide that came with your medicine.
- Severe stomach-area pain that will not go away, sometimes reaching your back, with or without vomiting. The guides say to stop the medicine and call your healthcare provider right away. It can be a sign of pancreatitis.
- Upper stomach pain, fever, yellow skin or eyes, or clay-colored stools. Call your provider. These can be gallbladder problems.
- Vomiting or diarrhea that does not go away. Tell your provider right away. The labels warn that fluid loss can lead to kidney injury, sometimes serious.
- Signs of a serious allergic reaction. Stop the medicine and get medical help right away.
If something is severe, sudden or frightening, get medical help. Do not wait to log it.
How Reko helps
Log how you are doing day by day, along with water and fiber. Reko keeps your symptoms beside your doses, so you can show your prescriber when something began and how it changed. It does not tell you what a symptom means, and it never suggests a dose.
Questions people ask
How long does GLP-1 constipation last?
One expert consensus reports a median of 47 days in people with obesity, longer than other stomach side effects. It can start in the first 16 weeks, particularly the first 28 days.
What foods help with constipation on a GLP-1?
A 2025 joint advisory suggests adding fiber gradually, for example prunes, and eating water-rich fruit and vegetables, along with enough fluids.
Can protein make GLP-1 constipation worse?
The advisory says high-protein or high-fat foods can make it worse, and that temporary limits may be needed. It also asks people to keep protein up, so ask a dietitian or your prescriber how to balance the two.
Is it safe to take a laxative with a GLP-1?
Expert groups mention polyethylene glycol, stool softeners, magnesium and fiber supplements. Ask your prescriber or pharmacist before starting one.
Can constipation cause diarrhea?
It can. The advisory notes that extended constipation can cause reactive diarrhea. If you have both, tell your provider.
How much water should I drink?
The sources we read give no fixed target for people on these medicines. The labels say it is important to drink fluids to reduce the chance of dehydration.
Reko records what you and your prescriber decide. This guide is general information and not medical advice.
Read next
Recipes to try
These are ordinary recipes and do not treat any side effect.
Useful tools
- Mounjaro prescribing information on DailyMed. Checked 2 November 2026.
- Zepbound prescribing information on DailyMed. Checked 2 November 2026.
- Ozempic prescribing information on DailyMed. Checked 2 November 2026.
- Wegovy prescribing information on DailyMed. Checked 2 November 2026.
- Gorgojo-Martínez JJ et al. Clinical recommendations to manage gastrointestinal adverse events in patients treated with GLP-1 receptor agonists: a multidisciplinary expert consensus. J Clin Med 12(1):145. An expert consensus, not a trial.
- Mozaffarian D et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint advisory. Am J Clin Nutr 2025;122(1):344-367. Mostly expert opinion.