GLP-1 gallbladder risk — the increased likelihood of gallstone formation observed in people using these medications — may develop through two proposed pathways: reduced signaling of the bile-releasing hormone CCK, which can slow gallbladder emptying, and the effect of rapid weight loss on bile composition. Both are biologically distinct mechanisms, and clinical studies have documented elevated gallstone rates across multiple GLP-1 medications.
If you’re taking a GLP-1 medication and want to understand the biology and evidence behind this risk, this article covers both mechanisms and what the research has noted. For symptoms and when to seek care, see GLP-1 Side Effects: What’s Normal — and When to Call Your Doctor.
What the Gallbladder Does and Where It Fits in Digestion
The gallbladder is a small, pear-shaped organ beneath the liver, on the right side of the abdomen. Its job is to store bile — a digestive fluid made by the liver — and release it into the small intestine when you eat, especially after meals that include fat. Bile helps the body break down and absorb dietary fats.
The release of bile is largely coordinated by a hormone called cholecystokinin, or CCK. When food reaches the small intestine, CCK signals the gallbladder to contract and push bile through the bile duct. That contraction is what makes the system work.
Gallstones form when substances in bile — most often cholesterol — crystallize rather than stay in solution. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) explains that this can happen when bile contains too much cholesterol, too much bilirubin, or not enough bile salts to keep cholesterol dissolved.
Most people who have gallstones never know it — the stones cause no symptoms and require no intervention. When a stone blocks a bile duct, however, it can cause pain and other effects that warrant medical evaluation. Whether any intervention is appropriate, and what kind, is a clinical judgment made by a provider who knows your full picture.
How GLP-1 Medications May Affect Bile and Gallbladder Function
GLP-1 receptor agonists work by mimicking a natural gut hormone that influences the pancreas, brain, and digestive system. One effect that has received increasing attention in clinical literature is their potential influence on gallbladder function — specifically through the CCK pathway described above.
A 2025 review by Ramírez-Mejía MM, Ponciano-Rodriguez G, Eslam M, and Méndez-Sánchez N in Therapeutic Advances in Endocrinology and Metabolism describes this mechanism directly: “GLP-1RAs reduce postprandial release of CCK, resulting in inadequate emptying of the gallbladder after meals.”
When the gallbladder doesn’t contract as fully or as often as it normally would, bile may remain there for longer periods. The same 2025 review explains what can follow: “This impaired contractility contributes to bile stasis, a situation in which bile remains in the gallbladder for prolonged periods, increasing the likelihood of cholesterol crystallization and gallstone formation.”
In plain terms: when the CCK signal is reduced, bile may sit and concentrate. Over time, concentrated bile may create conditions in which cholesterol crystallizes — one pathway through which gallstones can form in some people.
This is a proposed mechanism based on pharmacological reasoning and review of existing data. It is not a guaranteed outcome. Many people using GLP-1 medications do not develop gallstones, and individual variation is significant.
What Clinical Studies Have Found About Gallstone Formation
Beyond the proposed mechanism, clinical research has documented elevated rates of gallbladder-related conditions in people using GLP-1 medications. As noted in our guide to when to call your doctor, studies have associated GLP-1 use with increased gallbladder risk. The studies cited here provide additional detail on rates and population context.
Gameil et al. (2024) — A Real-World Cohort in Type 2 Diabetes
A 2024 multi-center observational study of 308 adults with type 2 diabetes (Gameil MA et al., Diabetology & Metabolic Syndrome, DOI: 10.1186/s13098-024-01526-2) examined cholelithiasis rates across three GLP-1 receptor agonists compared to conventional therapy. The study found overall cholelithiasis relative risk values of 1.2, 1.3, and 1.4 across the three agents, compared to the control group.
These are group-level findings within a specific population — adults with type 2 diabetes. They represent relative comparisons within that cohort and cannot be applied to any individual’s personal risk without a provider review.
Hurwitz et al. (2025) — A Large Retrospective Cohort Study
A 2025 real-world retrospective cohort study (Hurwitz SR et al., Pharmacoepidemiology and Drug Safety, DOI: 10.1002/pds.70214) examined GLP-1 receptor agonist safety across two distinct populations: those using the medication for type 2 diabetes management, and those using it specifically for chronic weight management.
For the type 2 diabetes population, gallbladder and biliary disease hospitalization showed a rate ratio of 1.14 (95% CI: 1.06–1.22) compared to a different drug class (SGLT2 inhibitors). For the chronic weight management population, the corresponding rate ratio was 3.32 (95% CI: 1.44–7.64) compared to users of other weight management medications.
The gap between 1.14 and 3.32 reflects the different populations and comparator drugs involved — not a simple dose-response relationship. The chronic weight management group was compared to users of entirely different medications; the type 2 diabetes group was compared to SGLT2 inhibitor users. As observational comparisons rather than randomized controlled trials, these findings carry the usual limitations: residual confounding, reporting bias, and differences in baseline health between groups may influence results.
Why Rapid Weight Loss Adds a Separate Layer of Risk
The CCK-mediated pathway described above is specific to GLP-1 receptor activity. A separate, independent pathway involves changes in bile composition that can accompany rapid weight loss — which may occur in some people using GLP-1 medications, but is not caused by GLP-1 receptor activity itself.
The NIDDK states directly: “Losing weight very quickly also may raise your chances of forming gallstones.” This reflects a pattern documented in the broader clinical literature: rapid shifts in body weight — regardless of how they are achieved — can alter the cholesterol and bile salt balance of bile in ways that may promote stone formation in some people.
The 2025 review by Ramírez-Mejía et al. also notes that “obesity, metabolic syndrome, rapid weight loss, and IR contribute to cholesterol stone formation by promoting hypersecretion of cholesterol into the bile and impairing gallbladder motility” — consistent with the understanding that rapid weight loss is an independent contributing factor, separate from the receptor-level mechanism.
For context on how rapid weight loss may relate to other physical changes during GLP-1 use, see our discussion in GLP-1 and Skin Changes. For people using GLP-1 medications who are also experiencing significant weight loss, these two pathways — the receptor-mediated effect and the weight-loss-mediated effect — may operate at the same time, though the degree to which each contributes varies by individual.
Who May Be More Likely to Develop Gallstones: What Data Suggest
Clinical data describe patterns at the population level — they cannot tell you whether you personally will develop gallstones. What they can outline is which group-level factors have been associated with higher rates in study populations.
The NIDDK identifies the following as general risk factors for gallstone formation: being female, being 40 or older, having overweight or obesity, having a family history of gallstones, experiencing rapid weight loss, having a history of pregnancy, and belonging to certain ethnic groups. These are population-level observations, not individual predictions.
Among people using GLP-1 medications, the Gameil et al. (2024) study found that the participants who developed cholelithiasis were drawn from a population already living with type 2 diabetes — a condition associated with metabolic factors that independently affect bile composition and gallbladder function. The Hurwitz et al. (2025) findings showed meaningful variation by indication (type 2 diabetes versus chronic weight management), which may reflect differences in baseline health, concurrent medications, or the degree of weight change experienced in each group.
What this suggests is that gallbladder risk on GLP-1 medications is not uniform. Providers typically assess these factors as part of ongoing monitoring. If you have pre-existing risk factors — including any history of gallbladder issues — this is a conversation worth having with your provider.
For symptoms like severe abdominal pain, fever, or yellowing of the skin or eyes, see our GLP-1 side effects and warning signs overview for what warrants prompt medical attention.
What to Discuss With Your Provider About Gallbladder Risk
Understanding the mechanism and evidence doesn’t tell you what to do about your individual situation — that is the provider’s role. What it can do is prepare you for a more informed conversation.
Some questions that may be worth raising at your next provider appointment, depending on your situation:
- “Are there any baseline gallbladder concerns I should be aware of, given my health history and current medication?”
- “What monitoring, if any, do you typically recommend for gallbladder health for people on this medication?”
- “If I notice new digestive symptoms, what is your preference for how I let you know?”
- “Is there anything about the rate of weight loss I am experiencing that relates to gallbladder function?”
These are not prescriptive recommendations — they are examples of the kind of factual questions some people find useful to have in mind before an appointment. Your provider may address these topics proactively, or may have information specific to your case that changes what is relevant to discuss.
Any decision about continuing, pausing, or modifying a GLP-1 medication in response to a clinical finding — including a gallbladder finding — is made in consultation with your prescribing provider. That decision belongs to you and your provider, not to a general article.
The GLP-1 Side-Effect & Progress Tracker can help you keep an organized record of what you notice between appointments — the kind of notes that may be useful to have when these conversations come up.
Two Pathways: How They Differ
| GLP-1 Receptor Pathway | Rapid Weight Loss Pathway | |
|---|---|---|
| Proposed mechanism | Reduced CCK release → reduced gallbladder emptying → bile stasis | Shifts in bile composition during rapid weight loss |
| GLP-1 specific? | Yes — linked to receptor activity | No — observed with rapid weight loss from any cause |
| Evidence basis | Pharmacological review (Ramírez-Mejía et al. 2025) + observational data | NIDDK guidance + clinical literature |
| Individual variation | Significant — not all users are affected | Significant — depends on rate and amount of weight change |
| Clinical implication | Monitored as part of GLP-1 safety profile | Discussed with provider as part of weight management plan |
For informational purposes only. Not medical advice. Consult your healthcare provider before making any changes to your medication or treatment plan. If you experience severe, persistent upper right abdominal pain — especially with fever, chills, or yellowing of the skin or eyes — seek prompt medical attention and do not wait. Call 911 for a medical emergency.