Gallbladder and biliary problems are among the best-documented GLP-1 side effects, and among the few that need more than home management. Part of the risk seems to come from the medication and part from rapid weight loss, and the two add to each other. This guide covers how large the risk is and which symptoms need a prompt call.
What the evidence shows
A 2022 systematic review and meta-analysis of 76 randomized clinical trials with more than 103,000 patients found GLP-1 receptor agonist use was associated with a significantly higher risk of gallbladder or biliary disease overall (relative risk 1.37). That included cholelithiasis (gallstones, RR 1.27), cholecystitis (gallbladder inflammation, RR 1.36), and broader biliary disease (RR 1.55) (He et al., JAMA Internal Medicine, 2022, DOI (external link)). In absolute terms the increase was small: about 27 extra cases per 10,000 people treated per year. A 2025 meta-analysis of 21 trials and nearly 100,000 patients found the same pattern, a 26% increase in gallbladder disorders with GLP-1 use, alongside cardiovascular benefits (Galli et al., JACC, 2025, DOI (external link)).
Why the risk goes up
Two things seem to drive it. Rapid weight loss is a known risk factor for gallstones whatever the method. The NIDDK notes that very low-calorie diets and weight-loss surgery both raise the risk, and that diets or surgeries causing fast weight loss are more likely to lead to gallstone problems than slower loss (NIDDK (external link)). The medication seems to add risk of its own as well. In Wegovy's weight-loss trials, gallstones were reported in 1.6% of adults on the injection compared with 0.7% on placebo, and the prescribing information says gallbladder disease was more common on Wegovy "even after accounting for the degree of weight loss" (Wegovy label (external link)). Whether that works through gallbladder motility, bile composition or both is less firmly established.
The 2022 meta-analysis found the risk was much higher in trials using GLP-1s for weight loss (RR 2.29) than in trials for diabetes or other conditions (RR 1.27). Across all 76 trials, the risk went up at higher doses (RR 1.56) and with longer use (RR 1.40), while lower doses (RR 0.99) and shorter use (RR 0.79) showed no clear increase.
Symptoms to watch for
Gallstones or gallbladder disease can cause sudden, severe pain in the upper right abdomen (often after eating, especially fatty food), pain that spreads to the back or shoulder, nausea or vomiting along with the pain, and fever. These symptoms need prompt medical attention; if gallstones are suspected, the Wegovy label calls for gallbladder studies and clinical follow-up. Unlike routine GI side effects, they aren't something to manage at home. Severe upper-abdominal pain spreading to the back can also be pancreatitis, which looks similar and is just as much a reason to get checked.
What this means in practice
For most people the absolute increase is small enough not to change the decision, and the 2025 analysis found GLP-1s reduced serious adverse events and mortality overall despite the higher gallbladder and GI risk. Know the warning signs, though, and don't write off upper right abdominal pain, especially after eating, as routine stomach upset.
This is general education, not medical advice. Sudden, severe upper right abdominal pain deserves prompt medical attention. Contact your prescriber or seek care instead of waiting it out.
Research summarized here was identified in part using PubMed; consult the linked sources.