In recent months, I have seen a noticeable increase in patients attending clinic with gallstone symptoms after using weight-loss injections such as Mounjaro® (tirzepatide) and Ozempic® (semaglutide). These medications can be highly effective for weight loss and diabetes management, but rapid weight loss itself is a well-recognised risk factor for gallstone disease.
Why Does Rapid Weight Loss Increase Gallstone Risk?
Two mechanisms are at work:
- Bile becomes more cholesterol-rich: During rapid weight loss, the liver releases extra cholesterol into bile. This shifts the bile composition towards the type that is more likely to crystallise and form stones.
- Gallbladder emptying slows: With reduced caloric and fat intake, the gallbladder contracts less frequently. Bile that sits static for extended periods is more prone to stone formation.
These mechanisms are not new. They were first recognised in the context of very-low-calorie diets and bariatric surgery. Weight-loss injections can produce similar effects, particularly when weight loss is fast and substantial.
Symptoms to Watch For
- Pain in the upper right or central abdomen, often after meals
- Pain radiating to the back or right shoulder tip
- Nausea or vomiting associated with meals
- Bloating or persistent indigestion-type symptoms
- Jaundice, dark urine, or fever — which may indicate stones in the bile duct and require urgent assessment
Should You Stop Your Medication?
Not necessarily, and certainly not without specialist advice. Many patients derive significant benefit from these medications, and stopping abruptly is not without consequence. However, new abdominal symptoms should never be ignored. The appropriate response is assessment, not assumption.
How Are Gallstones Treated?
If gallstones are causing symptoms, the most effective treatment is laparoscopic cholecystectomy — keyhole removal of the gallbladder. This is a well-established, safe procedure with a rapid recovery. In more complex cases involving the bile duct, specialist hepatobiliary expertise is essential.
A Note on Timing
If you are planning to continue with weight-loss injections and have no current symptoms, it is worth being aware of the risk and knowing what to look out for. If symptoms develop, early assessment is straightforward and prevents the kind of complications — bile duct obstruction, infection, pancreatitis — that require more complex treatment.