People taking popular new weight-loss drugs such as Wegovy and Zepbound often celebrate the number of pounds they shed and the related health benefits, but many doctors at weight-loss clinics are noticing a puzzling response in certain individuals. Andres J. Acosta, a gastroenterologist at the Mayo Clinic, says some of his patients have expressed frustration and disappointment as they watch friends or colleagues drop significant weight while taking the drugs but lose little or no weight themselves—even when they adhere to the medication’s instructions perfectly.

“They see themselves as a failure,” Acosta says. But the drugs’ effectiveness is likely outside of their direct control—scientists think their nonresponse could be related to what’s driving their excess weight in the first place.

Read the full article in Scientific American.