Gallstones are a known adverse effect of somatostatin analogs, but it was unclear when they arise on treatment and whether they lead to complications. Sophie Aapkes and Lucas Bernts used data from a 120-week clinical trial (DIPAK) that randomized patients with polycystic kidneys for lanreotide (120 mcg/month) or placebo. We assessed MRI scans for gallstones and found that 15% (19/124) of lanreotide users and 1% (1/125) patients on placebo developed incident gallstones. Gallstones were mostly multiple (> 20 stones) and small and 9/19 developed severe gallstone-associated complications in particular after stopping lanreotide.