Quick answer: GLP-1 constipation is common at weight-loss doses. It affected 24% of adults on Wegovy 2.4 mg versus 11% on placebo, and 11% to 17% on Zepbound versus 5% on placebo.[1][2] It tends to last longer than nausea or diarrhea, with a median episode of 47 days in the semaglutide STEP trials, and usually responds to fiber, fluids and activity.[5][6]
This guide is part of our GLP-1 basics hub. For every side effect side by side, see the GLP-1 side effects guide.
How common is constipation on each GLP-1?
| Drug and dose | Constipation | Placebo |
|---|---|---|
| Wegovy 2.4 mg (weight loss) | 24% | 11% |
| Wegovy 7.2 mg (weight loss) | 20% | 8% |
| Zepbound 5 / 10 / 15 mg (weight loss) | 17% / 14% / 11% | 5% |
| Ozempic 0.5 / 1 mg (diabetes) | 5.0% / 3.1% | 1.5% |
| Mounjaro 5 / 10 / 15 mg (diabetes) | 6% / 6% / 7% | 1% |
Sources: Wegovy, Zepbound, Ozempic and Mounjaro prescribing information.[1][2][3][4]
A few patterns stand out:
- Weight-loss doses cause more constipation than the diabetes versions. The trials also differed in population and length, so the rows are not a direct comparison.
- On Zepbound, constipation was highest at the lowest dose (17% at 5 mg versus 11% at 15 mg).[2]
- In a heart outcomes trial of 6,647 adults on Mounjaro, constipation was reported more often (13%) than in the shorter diabetes trials.[4]
- An expert consensus noted that constipation is reported more often in people with obesity than in people with type 2 diabetes.[6]
Why GLP-1 drugs cause constipation
GLP-1 drugs such as semaglutide and tirzepatide delay gastric emptying, meaning food leaves the stomach more slowly.[1][2] This helps you feel full but also changes how the gut moves. The authors of the STEP analysis suggested that constipation lasts longer than other stomach side effects because of these effects on gut motility.[5]
Everyday changes add to it. Eating much less means less food bulk and often less fiber, and many people drink less when their appetite falls. For more on how the drugs act, see how GLP-1 drugs work.
How long does GLP-1 constipation last?
In the STEP 1 to 3 trials of semaglutide 2.4 mg:[5]
- The median constipation episode lasted 47 days, compared with 35 days on placebo.
- Nausea, diarrhea and vomiting episodes were much shorter: medians of 8, 3 and 2 days.
- The share of people with constipation leveled off at about week 10.
So constipation is often the slowest side effect to settle. It still tends to improve over time, and 98.1% of stomach side effects in those trials were mild to moderate.[5]
Does constipation mean the drug is working?
No. In the STEP analysis, weight loss on semaglutide was about the same in people with and without stomach side effects, and less than 1 percentage point of the extra weight loss was explained by them.[5] Constipation is a side effect to manage, not a sign of a better result. It is also rarely a reason to stop: only 4.3% of people on semaglutide 2.4 mg stopped treatment because of any stomach side effect.[5] If it is wearing you down, raise it with your prescriber rather than skipping doses on your own. Our missed GLP-1 dose guide explains the label rules.
Ozempic, Mounjaro and Zepbound constipation
People often search for constipation by brand, but the cause is the same drug class:
- Ozempic and Wegovy both contain semaglutide. Ozempic’s lower doses produced less constipation in diabetes trials (3% to 5%) than Wegovy’s weight-loss dose (24%).[1][3]
- Mounjaro and Zepbound both contain tirzepatide. Constipation affected 6% to 7% on Mounjaro in diabetes trials and 11% to 17% on Zepbound in weight-loss trials.[2][4]
If you switch drugs or brands, constipation may return during the new dose escalation.
What helps GLP-1 constipation
A 2022 multidisciplinary expert consensus on managing GLP-1 stomach side effects recommends:[6]
- Get enough fiber. Fruit, vegetables, whole grains, beans and lentils add bulk. Increase fiber gradually.
- Drink generous amounts of water or other sugar-free fluids through the day.
- Move more. The panel advises increasing physical activity, such as regular walks.
- Consider a stool softener if diet and fluids are not enough. Ask your pharmacist which product suits you.
- Keep a food diary to spot foods or meal timings that make symptoms worse.
General tips from the same consensus also apply: eat slowly, choose smaller portions, and stop eating when you feel full.[6] Our GLP-1 diet guide covers high-fiber, high-protein meal ideas.
When constipation is a warning sign
Most GLP-1 constipation is uncomfortable but not dangerous. Rarely, it is part of something more serious.
- Blockage and impaction. Since approval, the semaglutide and tirzepatide labels list reports of ileus (the bowel stops moving), intestinal obstruction and severe constipation including fecal impaction.[1][2] These reports come from voluntary reporting, so their true frequency is unknown.
- Bowel obstruction in a database study. A 2023 study of US health records compared people using semaglutide or liraglutide for weight loss with people using bupropion-naltrexone. GLP-1 use was linked to a higher risk of bowel obstruction (hazard ratio 4.22), although the confidence interval was wide (1.02 to 17.40) and such studies cannot prove cause.[7]
- Gastroparesis. The labels say these drugs are not recommended in people with severe gastroparesis (very slow stomach emptying).[1][2]
Get urgent medical care if constipation comes with:
- severe or worsening belly pain or a swollen, hard belly
- vomiting, especially if you can’t keep fluids down
- no bowel movement and no passing of gas
- blood in your stool or black stools
- fever
Belly pain with fever can have other causes, such as diverticulitis; see our GLP-1 diverticulitis guide. If you have surgery or a procedure coming up, read GLP-1 before surgery.
Questions to ask your clinician
- Which stool softener or laxative is safe for me, and how often can I use it?
- Should I stay on my current dose longer before increasing?
- Could any of my other medicines be adding to the constipation?
- Which symptoms should send me to urgent care?
This guide is general information, not medical advice. Talk to a licensed clinician before changing your treatment.
