The Wegovy label includes acute gallbladder disease as a warning. The cardiovascular trial of semaglutide (SELECT) put numbers on it: gallbladder events showed up in about 1 in 36 people on the peptide versus about 1 in 43 on placebo. A small but real increase.

The mechanism is biliary chemistry: when body fat drops fast, cholesterol concentration in bile goes up, and slower gut motility lets gallstones form.

The same risk exists with bariatric surgery, very-low-calorie diets, and other rapid-weight-loss methods. The peptide contributes to the conditions; the speed of weight loss is the dominant lever.