Gallbladder problems in the GLP-1 labels

Where the warning sits

Acute Gallbladder Disease is a section 5 warning in all four labels: section 5.9 for Ozempic®, 5.3 for Wegovy®, 5.8 for Mounjaro® and 5.4 for Zepbound®. Trial numbers appear in section 6.1, and the Ozempic® label also lists gallbladder inflammation and gallbladder removal (cholecystectomy) among its postmarketing reports in section 6.2 ^[1][2][3][5].

The terms are worth knowing. Cholelithiasis means gallstones. Cholecystitis is inflammation of the gallbladder. Biliary colic is pain caused by the bile ducts, and a cholecystectomy is surgery to remove the gallbladder. The Wegovy® Medication Guide notes plainly that some gallbladder problems need surgery ^[2].

Gallstone rates against placebo

Each US label reports these events slightly differently, so the table names the measure used. Ranges cover dose groups, and section 6.1 warns that rates from different trials cannot be directly compared.

Inflammation, surgery and adolescents

Gallbladder inflammation was reported in 0.6% of adults on Wegovy® injection against 0.2% on placebo, and in 0.7% on Zepbound® against 0.2%. Gallbladder removal was reported in 0.2% on Zepbound® and in no one on placebo ^[2][5].

The Wegovy® label says rates were higher in adolescents aged 12 and older than in adults: gallstones in 3.8% on Wegovy® versus none on placebo, and inflammation in 0.8% versus none ^[2].

European and Canadian product information

The European Medicines Agency lists gallstones as “common”, at least 1 person in 100, for Ozempic® and Wegovy®, and gallstones and gallbladder inflammation as “uncommon”, at least 1 in 1,000, for Mounjaro® ^[7][8][9]. There is no European Zepbound® document, because tirzepatide is sold in the EU only as Mounjaro®.

What the meta-analyses found

Meta-analyses pool many randomised trials to estimate effects that single trials are too small to measure. A 2022 analysis of 76 trials with more than 103,000 people found GLP-1 medicines were linked to a higher risk of gallbladder and bile duct disease overall (relative risk 1.37). The increase was larger at higher doses, with longer use, and in weight-loss trials (relative risk 2.29) than in trials for diabetes and other conditions ^[11].

A 2025 analysis of 55 placebo-controlled trials with 106,395 people found the same direction for gallstones, with a relative risk of 1.46. In absolute terms that was about 2 extra cases per 1,000 people ^[12]. Both analyses covered several GLP-1 medicines together, so they do not give a figure for any one brand.

Why it may happen

What the labels support: the Wegovy® label says substantial or rapid weight loss can increase the risk of gallstones, but that gallbladder disease was still more common on Wegovy® than on placebo after accounting for how much weight people lost. Its counselling section adds that gallbladder disease may also occur without substantial or rapid weight loss ^[2]. The Zepbound® label and the European Mounjaro® information say acute gallbladder events were associated with weight reduction ^[5][9].

What is proposed but not measured: because the excess remained after accounting for weight loss, weight loss alone may not explain it. What else contributes is not described in the labels or in the two meta-analyses below.

General medical background: the NIH explains that when you go without food for long periods or lose weight quickly, the liver releases extra cholesterol into bile, and fast weight loss can stop the gallbladder emptying properly; repeated losing and regaining of weight may also raise the risk ^[14].

What else could it be

Gallstones are common on their own. The NIH lists women, older people, people with a family history, obesity, diabetes and insulin resistance, high triglycerides, and fast weight loss, for example after weight-loss surgery, as higher risk; MedlinePlus adds pregnancy and birth control pills ^[13][15]. Most gallstones cause no symptoms at all ^[13].

Upper stomach pain also has other causes. The NIH notes that gallstone symptoms can resemble appendicitis, ulcers, pancreatitis and reflux, all of which need a doctor ^[13]. Pancreatitis is a separate warning in the GLP-1 labels with a different instruction: if intense pain in the belly persists, at times spreading to the back, the guides say to stop the medicine and call your provider right away. Stomach pain appears in both lists, which is one reason to describe your pain accurately rather than decide for yourself which it is.

What general guidance says

The labels do not give lifestyle advice for the gallbladder. In the prescribing information, gallbladder tests and clinical follow-up are indicated if gallstones are suspected ^[1][2]. General NIH guidance on weight loss and gallstones, written for weight loss in general rather than for GLP-1 medicines, adds the following.

• Talk with your health care professional about how to lose weight safely, since losing weight very quickly can raise the chance of gallstones ^[14].
• Avoid crash diets and long periods without food, and aim to keep weight off rather than losing and regaining it ^[14].
• Regular physical activity may also lower the chance of gallstones ^[14].
• In people with obesity, MedlinePlus notes that avoiding rapid weight loss may help prevent gallstones, though in most people they cannot be prevented ^[15].

What to write down

If you have stomach pain, note where exactly it is, when it started, how long it lasted and whether it came after a meal, and what that meal was. Record any fever, any change in the colour of your skin, eyes, urine or stools, and whether nausea or vomiting came with it. The NIH notes that gallbladder attacks often follow heavy meals and tend to come in the evening or at night ^[13].

Because the labels connect gallbladder events with weight reduction, a dated weight record helps your clinician see how quickly you have been losing.

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.

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