Gallstones are the side effect most likely to turn into surgery, and the pooled evidence on them is stronger than for most things attributed to this drug class. A meta-analysis of 76 randomized trials in 103,371 patients found that randomization to a GLP-1 receptor agonist was associated with an increased risk of gallbladder or biliary disease, at a relative risk of 1.37 (95% CI 1.23 to 1.52) [1]. That is the figure usually quoted. It is not the figure that applies to most people reading a GLP-1 seller’s page.
The weight-loss subgroup is nearly twice as high
The analysis split trials by what they were studying. In the 63 trials for type 2 diabetes or other conditions, the relative risk was 1.27 (95% CI 1.14 to 1.43). In the thirteen trials for weight loss, it was 2.29 (95% CI 1.64 to 3.18), with a formal test for interaction at P < 0.001 — meaning the difference between those two groups is unlikely to be chance.
Everyone buying from a telehealth seller is in the second group. A doubled relative risk on an uncommon event is still an uncommon event, but it is the number that describes this population, and it is roughly twice the one that travels.
Dose and duration both moved it
Two further subgroup findings sharpen the picture. At higher doses the relative risk was 1.56 (95% CI 1.36 to 1.78); at lower doses it was 0.99 (95% CI 0.73 to 1.33), which includes no effect at all, with interaction at P = 0.006. With longer use it was 1.40 (95% CI 1.26 to 1.56) and with shorter use 0.79 (95% CI 0.48 to 1.31), interaction at P = 0.03.
Read together: the risk concentrates at higher doses held for longer, which is precisely the shape of a maintenance prescription. It is also why a seller’s silence about what happens at a higher dose is a clinical gap and not only a pricing one — a question we have counted across the market in who publishes a dose ladder.
What the components were
Broken out, the pooled risks were 1.27 for cholelithiasis (95% CI 1.10 to 1.47), 1.36 for cholecystitis (95% CI 1.14 to 1.62) and 1.55 for biliary disease (95% CI 1.08 to 2.22). These are gallstones, an inflamed gallbladder, and disease of the bile ducts. The cholecystectomy figure is the one that ends in an operating room.
What to do with it
This is an association measured in randomized trials, which is the strongest design available, and the authors are explicit that the risk is greatest at higher doses, for longer durations, and for weight loss. It is worth raising with whoever writes your prescription — and worth noticing how little most sellers publish about who that clinician is, which we have measured in what sellers will not tell you and listed as questions they leave open.