Short answer: It has been reported, and all four US labels carry a warning, but it was rare in the trials. In the main diabetes and weight-loss trials, confirmed cases ran at 0.14 to 0.3 per 100 patient-years on the medicine; in the Zepbound weight-loss trials the rate was 0.2% on both Zepbound and placebo. The sign the labels describe is severe stomach pain that will not go away, sometimes felt through to the back, with or without vomiting. They say to stop the medicine and call a provider right away.
In these trials, a panel of experts checked each suspected case (adjudication) before counting it. Most labels give the rate per 100 patient-years: 0.2 per 100 patient-years means about 2 cases for every 1,000 people followed for a year.
| Medicine and trials | On the medicine | Comparison group |
|---|---|---|
| Wegovy, adults, weight reduction | 4 people (0.2 per 100 patient-years) | 1 on placebo (under 0.1) |
| Ozempic, type 2 diabetes trials | 7 people (0.3 per 100 patient-years) | 3 on comparator (0.2) |
| Mounjaro, type 2 diabetes studies | 13 people, 14 events (0.23 per 100 patient-years) | 3 on comparator (0.11) |
| Zepbound, weight reduction (Studies 1 and 2) | 0.2% (0.14 per 100 patient-years) | 0.2% on placebo (0.15) |
| Zepbound, sleep apnea (Studies 5 and 6) | 0.84 per 100 patient-years | 0 on placebo |
The Ozempic and Mounjaro comparison groups include other diabetes medicines, not only placebo. The trials also differ in who took part and for how long, so the rows are not a ranking of one medicine against another.
The labels also list acute and necrotizing pancreatitis, sometimes resulting in death, among reports received after approval. Reports like these come from a population of unknown size, so they show that something has happened, not how often.
Chiang and colleagues pooled 55 placebo-controlled trials with 106,395 people taking GLP-1 medicines for type 2 diabetes, overweight or obesity, or fatty liver disease, and looked at a list of gut and gallbladder problems that included pancreatitis.
They found a higher risk of gallstones (risk ratio 1.46, about 2 more cases per 1,000 people) and probably of acid reflux (2.19, about 4 more per 1,000). For the other problems they looked at, pancreatitis among them, they concluded GLP-1 medicines probably have little or no effect on risk.
That fits the low trial rates in the table. It does not remove the warning: the labels keep it because cases, including severe ones, have been reported, and because the condition is serious when it does happen.
The patient leaflets for Wegovy, Ozempic, Mounjaro and Zepbound use nearly the same words: stop using the medicine and call your healthcare provider right away if you have severe pain in your stomach area (abdomen) that will not go away, with or without vomiting. They add that the pain may be felt from the abdomen through to the back.
This is different from the everyday stomach upset that is common on these medicines. Nausea, stomach (abdominal) pain and constipation are among the common side effects the labels list; the pancreatitis warning is about pain that is severe and does not ease. Pain in the upper stomach with fever, yellow skin or eyes, or clay-colored stools is listed separately as a sign of gallbladder problems.
Before starting, the leaflets ask you to tell your provider if you have or have had problems with your pancreas. For prescribers, the labels say to watch for signs of pancreatitis after starting, and to stop the medicine and manage the condition if it is suspected.
Amylase and lipase are enzymes made by the pancreas. All four labels report that their blood levels rise on average during treatment:
The labels say the meaning of these rises is unknown when there are no other signs of pancreatitis. If you have blood work done for any reason, telling the lab or doctor which medicine you take helps them read the result. Dose Track keeps doses, side effects and lab results together, so the timing of any pain or test is easy to show.
Read more on Dose Track: Nausea on GLP-1s: what the labels say · GLP-1 side effects week by week · Wegovy side effects · Ozempic side effects · Mounjaro side effects · Zepbound side effects · GLP-1 receptor agonist (glossary)