The short answer: Yes. The FDA label for Mounjaro lists acute gallbladder disease as a warning. In placebo-controlled trials in adults, 0.6% of people on Mounjaro reported it, compared with 0% on placebo. The risk is real but small, and part of it comes from losing weight quickly, which raises gallstone risk on its own.
What does the Mounjaro label say about gallbladder disease?
Mounjaro and Zepbound contain the same drug, tirzepatide. Both labels carry a warning for acute gallbladder disease.
The Mounjaro prescribing information states that gallstones (cholelithiasis) and gallbladder inflammation (cholecystitis) have been reported in GLP-1 receptor agonist trials and after approval. It tells clinicians to order gallbladder studies and follow up if they suspect gallstones.
The Zepbound prescribing information is more direct. It says treatment with Zepbound and GLP-1 receptor agonists "is associated with an increased occurrence of acute gallbladder disease." It also says that acute gallbladder events were associated with weight reduction.
Neither label lists a history of gallstones as a reason you cannot take the drug. Neither label tells people to stop the drug because of gallbladder disease. That decision belongs to your prescriber.
How common were gallbladder problems in the trials?
The numbers are low in both labels. They differ because the two drugs were studied in different groups of people.
- Mounjaro (type 2 diabetes trials): acute gallbladder disease, defined as gallstones, biliary colic, or gallbladder removal, was reported by 0.6% of Mounjaro-treated adults and 0% of placebo-treated adults.
- Zepbound (two weight reduction trials, pooled): gallstones were reported in 1.1% of Zepbound-treated patients and 1% of placebo-treated patients.
- Zepbound, cholecystitis: 0.7% of Zepbound-treated patients and 0.2% of placebo-treated patients.
- Zepbound, gallbladder removal: 0.2% of Zepbound-treated patients and no placebo-treated patients.
Read those figures with care. In the weight reduction trials, gallstones were about as common on placebo as on the drug. The gap shows up in inflammation and surgery, which are the events that send people to the hospital.
The two brands share one molecule, so the difference is in who takes them and how much weight they lose. Our Mounjaro vs Zepbound comparison covers the other label differences.
Why does rapid weight loss itself cause gallstones?
Fast weight loss changes your bile. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) explains two effects. When you lose weight quickly, your liver releases extra cholesterol into the bile. Fast weight loss can also stop the gallbladder from emptying properly.
NIDDK says gallstones may form when bile contains too much cholesterol. They may also form when the gallbladder does not empty completely or often enough. Rapid weight loss pushes both in the wrong direction.
This is not unique to tirzepatide. NIDDK says diets or surgeries that cause fast weight loss are more likely to lead to gallstone problems than slower methods. It names very low-calorie diets and weight-loss surgery as examples.
Obesity is a gallstone risk factor before any treatment starts. NIDDK notes that people with obesity may have more cholesterol in their bile and gallbladders that do not work well. NIDDK also says that people with silent gallstones may develop symptoms during rapid weight loss.
Tirzepatide can produce large weight changes. See Mounjaro weight loss results for what the trials reported.
What do meta-analyses of GLP-1 drugs and tirzepatide show?
Pooled trial data point the same way as the labels.
A 2022 meta-analysis in JAMA Internal Medicine pooled 76 randomized trials with 103,371 patients. People assigned to a GLP-1 receptor agonist had a higher risk of gallbladder or biliary disease than people assigned to placebo or a non-GLP-1 drug (relative risk 1.37, 95% CI 1.23 to 1.52). A relative risk of 1.37 means the event rate was about 37% higher than in the comparison group.
That analysis covered GLP-1 receptor agonists as a class. Three of its findings matter here:
- The relative risk was 2.29 in the 13 weight loss trials and 1.27 in the 63 trials for type 2 diabetes or other diseases, each versus the control group.
- The risk was raised at higher doses (relative risk 1.56 versus control) and not at lower doses (relative risk 0.99 versus control).
- The risk was raised with longer use (relative risk 1.40 versus control) and not with shorter use.
A 2025 meta-analysis in the Journal of Diabetes Investigation looked at tirzepatide alone. It pooled 12 randomized trials with 12,351 patients who had type 2 diabetes or obesity. Compared with placebo or other glucose-lowering drugs, tirzepatide was associated with gallbladder or biliary disease (relative risk 1.52, 95% CI 1.17 to 1.98) and with gallstones (relative risk 1.67, 95% CI 1.14 to 2.44). The authors found no dose-response relationship across tirzepatide doses.
Relative risks sound large. The absolute rates in the labels are about 1% or less. A higher relative risk applied to a rare event still gives a rare event.
The same class effect applies to semaglutide. ozempic.md and glp1.md cover the other drugs in this group.
What symptoms need prompt care?
The Mounjaro Medication Guide tells patients to contact their healthcare provider right away for symptoms of gallbladder problems. It lists four:
- pain in your upper stomach (abdomen)
- fever
- yellowing of skin or eyes (jaundice)
- clay-colored stools
NIDDK describes a gallbladder attack as pain in the upper right abdomen that can last several hours. Attacks often follow heavy meals and usually happen in the evening or at night.
NIDDK says to see a doctor right away if an attack comes with any of these: abdominal pain lasting several hours, nausea and vomiting, fever or chills, jaundice, or tea-colored urine and light-colored stools. These can be signs of a serious infection or inflammation of the gallbladder, liver, or pancreas.
Nausea and mild stomach upset are common on Mounjaro, so the two can be confused. Pain that is severe, fixed in the upper abdomen, and lasts for hours is different from routine nausea. Our guide to managing Mounjaro side effects covers the common stomach effects.
The Zepbound label also warns about pancreatitis, with severe abdominal pain that may spread to the back. Gallstones can cause pancreatitis, so do not wait on severe pain.
Who is at higher risk?
NIDDK says gallstones affect 10 to 15 percent of the U.S. population. Many people who start Mounjaro already have a higher baseline risk. NIDDK lists these groups as more likely to develop gallstones:
- women, especially with extra estrogen from pregnancy, hormone replacement therapy, or birth control pills
- older people
- people with a family history of gallstones
- American Indians and Mexican Americans
- people with obesity, diabetes, insulin resistance, or metabolic syndrome
- people with high triglycerides or low HDL cholesterol
- people who have had fast weight loss
Type 2 diabetes and obesity are the reasons most people take tirzepatide. Both appear on that list. The meta-analysis data add longer treatment and use for weight loss as factors for GLP-1 drugs as a class.
NIDDK notes that losing weight at a slower pace may make gallstones less likely. It also says the medicine ursodiol can help prevent gallstones during very low-calorie diets or after weight-loss surgery. The tirzepatide labels do not mention ursodiol, so ask your prescriber before you assume it applies to you.
Tell your prescriber if you have had gallstones or a gallbladder attack before. Do not change your dose yourself to slow weight loss.
The bottom line
Mounjaro can cause gallbladder problems, and the FDA label says so. The trial rates were low: 0.6% on Mounjaro versus 0% on placebo, and about 1% or less for each event type in the Zepbound trials. Meta-analyses confirm a higher relative risk for tirzepatide and for GLP-1 drugs as a class. Rapid weight loss explains part of that risk. Know the warning signs, and get prompt care for severe upper abdominal pain, fever, jaundice, or pale stools.
Last updated: October 2026. This article is for informational purposes only and does not constitute medical advice. Talk with your healthcare provider about your own gallbladder risk before you start, stop, or change Mounjaro.