What section 5 says
Acute pancreatitis, inflammation of the pancreas, is a section 5 warning in each label: 5.2 for Ozempic®, Wegovy® and Mounjaro®, and 5.5 for Zepbound®. The wording is nearly identical across labels: people treated with GLP-1 receptor agonists, or with the medicine itself, have developed acute pancreatitis, including hemorrhagic or necrotizing forms, some of them fatal [1][2][3][5].
The labels tell prescribers to watch for persistent or severe abdominal pain, sometimes radiating to the back, which may or may not come with nausea or vomiting, and to stop the medicine if pancreatitis is suspected. Section 6.2 of each label lists acute pancreatitis among postmarketing reports, including necrotizing forms that sometimes resulted in death.
Confirmed cases in the trials
The labels report cases that were confirmed by adjudication, meaning an independent review. Rates are given per 100 patient-years: roughly, cases for every 100 people followed for a year. Some trials compared against placebo, others against other diabetes medicines.
| Label and trial pool | Comparison group | Medicine |
|---|---|---|
| Ozempic®: glycemic control trials [1] | 3 people, 0.2 per 100 patient-years | 7 people, 0.3 per 100 patient-years |
| Wegovy®: adult weight trials [2] | 1 person, under 0.1 | 4 people, 0.2 |
| Mounjaro®: clinical studies [3] | 3 people, 0.11 | 13 people, 0.23 |
| Zepbound®: Studies 1 and 2 [5] | 0.2% of people, 0.15 | 0.2% of people, 0.14 |
How to read those numbers
The case counts are small, which is why the labels do not attach a precise risk to them, and section 6.1 of each label warns that rates from different trials cannot be compared directly. In the Zepbound® weight trials the rate was the same on the medicine and on placebo. In its two sleep apnea trials the label gives 0.84 cases per 100 patient-years on Zepbound® and none on placebo [5].
Rare is not the same as negligible. The postmarketing reports in section 6.2 include deaths, and that is why the instruction for this symptom is firmer than for most side effects.
European and Canadian product information
The European Medicines Agency lists acute pancreatitis as “uncommon”, meaning at least 1 person in 1,000 but fewer than 1 in 100, for Ozempic®, Wegovy® and Mounjaro® [7][8][9]. There is no European Zepbound® document, because tirzepatide is sold in the EU only as Mounjaro®.
The European information also reports confirmed cases from large outcome trials. For Ozempic®, they occurred in 0.3% versus 0.2% on comparators in the main trials and 0.5% versus 0.6% on placebo in a 2-year cardiovascular trial. For Wegovy®, they occurred in 0.2% versus under 0.1% in the weight trials and 0.2% versus 0.3% in SELECT [7][8].
The Canadian Zepbound® monograph adds two practical points: the medicine has not been evaluated in people with a previous history of pancreatitis and should be used with caution in them, and if pancreatitis is confirmed it should not be restarted [10].
What the meta-analyses found
Because single trials see so few cases, researchers pool them. A 2023 meta-analysis of 43 randomised trials lasting at least a year in people with type 2 diabetes found no clear association between GLP-1 medicines and pancreatitis (odds ratio 1.24, with a confidence interval running from 0.94 to 1.64) [11].
A 2025 meta-analysis of 55 placebo-controlled trials, which also included people with obesity, concluded that GLP-1 medicines probably have little or no effect on the risk of pancreatitis and several other serious digestive events, while raising the risk of gallstones [12]. Trials can still miss rare or delayed events, which is why the labels keep the warning and the stop-and-call instruction.
Enzyme changes on blood tests
The labels also report rises in two pancreatic enzymes, amylase and lipase, in people without pancreatitis. Average lipase rose by 22% on Ozempic®, 39% on Wegovy®, 31% to 42% on Mounjaro® and 28% to 35% on Zepbound® in their trial pools, with smaller or no changes on placebo [1][2][3][5].
The Wegovy®, Mounjaro® and Zepbound® labels say that, without other signs or symptoms of pancreatitis, it is not known what these rises mean clinically. The Canadian Zepbound® monograph says raised enzymes alone do not predict pancreatitis [10]. If a blood test shows raised enzymes, interpreting it is a job for your clinician.
Why it may happen
What the labels support: acute pancreatitis has been reported in people on these medicines, in trials and after approval, and the labels treat it as a serious warning [1][2][3][5].
What is proposed but not measured: the labels do not describe a mechanism, and the meta-analyses did not find a clear excess in trials [11][12]. Whether the medicines cause pancreatitis in some people, or whether reports reflect the conditions of the people taking them, is not settled by the sources here.
General medical background: the NIH explains that pancreatitis happens when the pancreas’s digestive enzymes damage the organ itself, and names gallstones as one of its most common causes [13][14]. Gallstones are themselves a separate warning in the GLP-1 labels, so the two warnings can be linked in a single episode.
What else could it be
Pancreatitis has many causes unrelated to GLP-1 medicines. The NIH lists gallstones, heavy alcohol use, genetic disorders and some medicines as the most common, with infections, abdominal injury and certain procedures among others. It names diabetes, high triglycerides, obesity, smoking and a family history as factors that make pancreatitis more likely [13][14]. MedlinePlus adds medicines such as estrogens, corticosteroids, thiazide diuretics and azathioprine [15].
Other painful stomach conditions can look similar. Gallbladder attacks, ulcers and appendicitis all need a doctor, and only tests can tell them apart [13].
Not every stomach ache
Milder stomach pain, nausea and vomiting are common on these medicines and appear in the labels as ordinary adverse reactions; nausea and vomiting in particular cluster around dose increases. What sets the pancreatitis warning apart is pain that is severe and does not go away. MedlinePlus describes pancreatitis pain as usually felt in the upper left or middle of the abdomen, becoming constant and severe, sometimes worse lying flat and spreading to the back; people often look ill, with fever, nausea, vomiting and sweating [15].
If you are unsure which you are dealing with, put that question to your provider promptly rather than wait.
What to write down
If you have stomach pain, note when it started, exactly where it is, whether it spreads to your back, how strong it is on a simple 0 to 10 scale, and whether it is constant or comes and goes. Add whether you vomited, whether it followed a meal, how many days it was after your injection and whether your dose had recently gone up. In a severe episode, getting care comes first; the notes can be written afterwards.
Ozempic® and Wegovy® are registered trademarks of Novo Nordisk A/S. Mounjaro® and Zepbound® are registered trademarks of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.
When to get help
| Sign | Who to contact | How fast | Source |
|---|---|---|---|
| Intense stomach pain that persists, with or without vomiting, sometimes spreading to the back | Stop the medicine and call your healthcare provider right away | Emergency | Medication Guides [4][6] |
| Severe or worsening belly pain with fever or chills, a fast heartbeat, shortness of breath or yellowing of the skin or eyes | Seek care right away | Emergency | NIH (NIDDK) [13] |
| Upper stomach pain with nausea and vomiting, looking and feeling seriously ill | A doctor, right away | Emergency | NIH (NIDDK) [13] |
| A blood test showing raised amylase or lipase, without symptoms | Your prescriber | At your next appointment | US labels [2][3][5] |
| A past history of pancreatitis, before starting or continuing treatment | Your prescriber | At your next appointment | Medication Guides [4][6]; Canadian monograph [10] |
