The answer so far
The gallbladder is a small organ under the liver that stores bile, a fluid involved in digesting fat. Stones can sometimes block a bile duct or cause inflammation.
Gallbladder problems have been reported more often in some trials of weight-loss medicines than with placebo, although most participants did not report them. The 2026 US Wegovy and Zepbound labels describe different events and study populations. A person with concerning abdominal pain needs medical assessment; a trial average cannot diagnose the cause or predict an individual’s risk.12
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Can weight-loss medicines cause gallbladder problems? Choose a step to explore this subject in more detail.
What did Wegovy trials report?
In adult weight-reduction trials described in a 2026 US label, gallstones were reported by 1.6% of people receiving Wegovy injection (semaglutide), compared with 0.7% receiving placebo: roughly 1.6 versus 0.7 people per 100. Gallbladder inflammation was reported by 0.6% versus 0.2%. These are reported events in the specific trials, not a prediction for an individual; tablets and other populations have separate results.1
What did Zepbound trials report?
In two pooled weight-reduction trials in a 2026 US label, gallstones were reported by 1.1% of people receiving Zepbound (tirzepatide) and 1.0% receiving placebo. Gallbladder inflammation was reported by 0.7% versus 0.2%. Gallstones and inflammation are different outcomes and the numbers should not be added as if they were independent people. These trials and the Wegovy trials were not a direct head-to-head comparison.2
Why might gallbladder events occur?
Gallstones can form for several reasons, including changes in bile and incomplete gallbladder emptying. Weight loss itself can affect gallstone risk. The product labels associate some gallbladder events with weight reduction; that does not establish the precise cause in every patient or mean the medicine is the only possible factor. Risk depends on personal and medical circumstances.
A 2022 systematic review pooled 76 randomized trials of several GLP-1 receptor agonists, involving about 103,000 people treated for diabetes, weight loss or other conditions. Across these studies, the relative risk of a combined gallbladder or bile-duct outcome was 37% higher with a GLP-1 medicine than with the comparison treatment. The authors estimated about 27 additional events per 10,000 people treated per year on average. That is a pooled estimate across different medicines, populations and follow-up periods, not a personal risk or a direct estimate for Zepbound; it should not be added to the separate product-label figures above. The review searched studies through 2021 and does not include all later evidence.345
When should someone seek care?
Gallbladder attacks can cause pain in the upper right abdomen; symptoms can overlap with other conditions. NIDDK advises prompt medical care for abdominal pain lasting several hours, nausea or vomiting, fever or chills, yellow skin or eyes, dark urine or pale stools during or after an attack. Severe or persistent symptoms should not be dismissed as routine medicine-related nausea. A clinician can assess the cause and the appropriate next steps. For urgent symptoms and the separate evidence on pancreas inflammation, see GLP-1 medicines and pancreatitis.3
What do these figures mean for a particular product?
The cited percentages concern named US products, adult trial groups and reported outcomes over the studies’ follow-up. They do not describe every semaglutide or tirzepatide product, every indication, or an individual’s chance of harm. Product benefits and other risks also matter. Discuss symptoms and the exact medicine with a prescriber rather than changing a prescribed treatment based only on a general article. Read the semaglutide and tirzepatide profiles for broader context.12
Sources, kept close.
Selected supporting sources; this is not a complete literature review.
- Wegovy prescribing information, 2026U.S. Food and Drug Administration / Novo Nordisk · US product label; pooled clinical trial safety reports
- Zepbound prescribing information, 2026U.S. Food and Drug Administration / Eli Lilly · US product label; pooled clinical trial safety reports
- Symptoms & Causes of GallstonesU.S. National Institute of Diabetes and Digestive and Kidney Diseases · US public health guidance, reviewed 2017
- Dieting & GallstonesU.S. National Institute of Diabetes and Digestive and Kidney Diseases · US public health guidance
- Association of Glucagon-Like Peptide-1 Receptor Agonist Use With Risk of Gallbladder and Biliary DiseasesJAMA Internal Medicine · Systematic review and meta-analysis of randomized trials