Short answer
Zepbound constipation is common. In the two main weight trials, constipation was reported by 17% of people on 5 mg, 14% on 10 mg and 11% on 15 mg, against 5% on placebo. The Medication Guide says to tell your healthcare provider if stomach problems are severe or will not go away.
Source: Two main weight trials (Zepbound label, revised 08/2026)
How common it is, by dose
The label pools two placebo-controlled trials of 2,519 adults treated with Zepbound for up to 72 weeks. Constipation, which the label counts together with hard stools, was reported by 17% on 5 mg, 14% on 10 mg and 11% on 15 mg, against 5% on placebo. Unlike nausea and vomiting, the rate was highest on the lowest dose. The label does not explain why. Taken together, stomach and bowel side effects of any kind affected 56% of people on each Zepbound dose and 30% on placebo.
When it happens
The label does not give a time course for constipation. It says most nausea, vomiting and diarrhea happened during dose escalation and decreased over time, and the SURMOUNT-1 trial report said most stomach side effects were mild to moderate and occurred mainly during escalation. Whether constipation follows the same pattern is not stated. The step-up schedule is there to reduce stomach side effects: 2.5 mg once a week for 4 weeks, then increases of 2.5 mg after at least 4 weeks on each dose.
The label's warning on severe stomach reactions
Section 5.2 of the label warns that Zepbound has been linked to stomach and bowel reactions that are sometimes severe. In the weight trials, severe reactions were reported by 1.7% on 5 mg, 2.5% on 10 mg and 3.1% on 15 mg, against 1% on placebo. The label says Zepbound is not recommended for people with severe gastroparesis. Since approval, reports have included ileus, intestinal obstruction and severe constipation including fecal impaction. These reports are voluntary, so the label says their frequency cannot be reliably estimated.
When to call your provider
The Medication Guide asks you to tell your provider before starting if you have severe stomach problems such as slowed stomach emptying. During treatment, it says to tell your provider if stomach problems are severe or will not go away, and right away if nausea, vomiting or diarrhea does not go away, because fluid loss can harm the kidneys. Severe stomach pain that will not go away means stop Zepbound and call right away. The label does not recommend any laxative, so ask your prescriber or pharmacist what to use.
Related questions
Do people stop Zepbound because of stomach side effects?
Some do. In the two main weight trials, 1.9% on 5 mg, 3.3% on 10 mg and 4.3% on 15 mg stopped because of stomach and bowel reactions, against 0.5% on placebo.
Does Zepbound slow digestion?
The label says Zepbound delays gastric emptying. That is why it warns about the absorption of some oral medicines and about aspiration during anesthesia.
Is constipation listed in the Medication Guide?
Yes. Constipation is on the Medication Guide's list of the most common side effects, along with nausea, diarrhea and vomiting.
Read next
Sources
- Eli Lilly: Zepbound prescribing information and Medication Guide (revised 08/2026)
- Eli Lilly: Zepbound prescribing information, PDF (2026)
- Eli Lilly: Zepbound Medication Guide, PDF (revised 08/2026)
- New England Journal of Medicine: Tirzepatide Once Weekly for the Treatment of Obesity, Jastreboff (2022)
Published 2026-10-07 · Last checked 2026-10-07
Educational content, not medical advice. Made for the United States.