Constipation on Mounjaro: Why It Happens and How to Keep Track

Both Mounjaro and Wegovy work partly by slowing gastric emptying — the rate at which food moves from the stomach into the digestive tract. This effect, which is linked to their action on GLP-1 receptors (and, in tirzepatide's case, GIP receptors too), is useful for reducing appetite and increasing feelings of fullness, but it can also slow the entire digestive process further along, making constipation more likely.

When does it typically happen?

Constipation on Mounjaro or Wegovy is most commonly reported in the first few weeks of starting the medicine or shortly after a dose increase. Many people find it settles over time as their digestive system adjusts, though this varies from person to person. If you are eating less overall — which is common on these medicines — a lower food intake can also reduce bowel frequency independently of the medication itself.

General comfort measures worth knowing about

Staying well hydrated and including fibre-rich foods in your meals are two widely recognised general approaches to supporting digestive comfort. These are not specific medical treatments — they are general healthy habits that many people already follow. How much fluid and fibre is right for you personally is something to discuss with your prescriber or doctor, particularly if you are also managing other health conditions.

If your constipation is severe, has come on suddenly, is accompanied by significant abdominal pain, or does not improve, contact your healthcare professional promptly rather than waiting it out. You can find factual information about commonly reported side effects of semaglutide and tirzepatide on the electronic Medicines Compendium (eMC), which hosts the official patient information leaflets.

For more on the full range of side effects associated with tirzepatide, see our overview of Mounjaro side effects. If you are specifically looking for more detail on practical steps, our page on what to take for constipation on Mounjaro covers this topic further. Those taking semaglutide may also find our dedicated page on constipation on Wegovy useful.

One of the most useful things you can do when experiencing a side effect like constipation is to keep a clear record — when it started, how it relates to your dose schedule, how long it lasts, and whether it shifts as time goes on. This is exactly where GLP Trackr's side-effect tracking feature comes in.

Within the app, you can log symptoms — including digestive discomfort — alongside the date, your dose, and how you are feeling generally through the daily check-in. Over time, the insights tools can help you see whether your symptoms are tied to specific points in your injection cycle, making it much easier to describe your experience accurately when you speak to your prescriber or doctor.

You can also use the app's dose and injection logging to keep a clear record of when each dose was taken, so you can cross-reference any pattern between dose adjustments and changes in your digestive symptoms. If you are also tracking your food and fluid intake, the nutrition logging tools — including manual entry, barcode scan, and AI photo scan — let you see whether changes in what you are eating might be playing a role too.

GLP Trackr is not a substitute for clinical advice, and it does not tell you how to treat any symptom. What it does is give you a well-organised picture of your journey to bring to your appointments. Any decision about how to manage constipation medically — whether to try a specific remedy or adjust anything about your treatment — should be made with your prescriber, not on your own.

You can also read our page on being constipated on Mounjaro for more on what people commonly experience. For the broader picture of side effects and how to track them, head back to the Mounjaro side effects hub.

If logging your symptoms and spotting patterns sounds useful, GLP Trackr is free to try — download it on the App Store or Google Play and explore everything with a 7-day free trial.