Short answer: The labels do not list gastroparesis as a side effect, but all four slow stomach emptying as part of how they work, and all say they are not recommended for people who already have severe gastroparesis. Meta-analyses put the delay at about 36 to 74 extra minutes for half the stomach to empty. Reports after approval include ileus and bowel blockage.
Ozempic, Wegovy, Mounjaro and Zepbound all say they delay gastric emptying (section 12.2), meaning food leaves the stomach more slowly. For tirzepatide, the Mounjaro and Zepbound labels say the delay is largest after the first dose and shrinks over time. The Ozempic label calls it a minor delay early after a meal.
Each label has a warning on severe stomach and bowel reactions and ends it the same way: the medicine "is not recommended in patients with severe gastroparesis." The Ozempic, Mounjaro and Zepbound Medication Guides ask you to tell your provider before starting if you have severe stomach problems, such as slowed emptying of your stomach (gastroparesis).
None of the four labels lists gastroparesis itself among side effects. They do list ileus (the gut stopping moving), intestinal obstruction and severe constipation from reports after approval; constipation on GLP-1 medicines covers those.
| Study | What it pooled | Finding |
|---|---|---|
| Hiramoto 2024 | 15 studies; 5 used a scan of a solid meal (247 people) | Half-emptying time 138 vs 95 minutes, about 36 minutes longer; no clear delay on a liquid test |
| Chen 2026 | 10 prospective studies (300 people) | About 74 minutes longer; larger with short-acting drugs and in the first 10 weeks; very low certainty |
Hiramoto found that the type of GLP-1 medicine and how long people had taken it did not change the result. Chen found a trend toward more delay with short-acting medicines and early in treatment. Both were about measuring emptying, not about how many people developed gastroparesis.
The NIDDK lists the symptoms of gastroparesis as feeling full soon after starting a meal, feeling full long after eating, nausea, vomiting, too much bloating or belching, upper belly pain, heartburn and poor appetite. Many of these are also the common side effects of GLP-1 medicines.
The NIDDK makes a useful distinction for other medicines that slow the stomach, such as opioid pain medicines and pramlintide: they can cause gastroparesis-like symptoms and make existing gastroparesis worse, but it says these medicines do not cause gastroparesis. Its list does not mention GLP-1 medicines, so the page does not settle that question for them.
The Wegovy label reports severe stomach and bowel reactions in 4.1% of people on the injection vs 0.9% on placebo in adult weight-loss trials. The NIDDK says to get help right away for severe belly pain or cramping, vomiting for more than an hour, blood or coffee-ground material in vomit, or signs of dehydration.
Slower emptying also matters for surgery and for other pills. The labels report rare cases of food breathed into the lungs under anesthesia; see GLP-1 medicines before surgery. Logging nausea, fullness and vomiting next to each dose and dose step, as Dose Track does, shows whether symptoms ease as the labels describe or keep building.
Read more on Dose Track: GLP-1 nausea: what the labels say · GLP-1 medicines before surgery · Ozempic side effects · Zepbound side effects · Gut health