Anti-obesity medication use sparks effort-based sanctions and social penalties.

Obesity is one of the most widespread public health risks, with more than 1 billion affected individuals worldwide. While treatment with 'anti-obesity' medication (GLP-1 agonists) shows promising results, patients face public backlash for 'cutting corners'. Across four pre-registered within-subject studies in three countries (N = 1.205, Belgium, US, UK), we found that users of GLP-1 medication are perceived as less moral, presumably because they are thought to have exerted less effort in their weight-loss endeavor. Further, we observed effects on broader consequences (e.g., competence or deservingness perceptions) and tested candidate moderators (e.g., attitudes, experience, personality). Our findings highlight the adverse consequences of effort-based biases experienced by patients using anti-obesity medication and underscore the need for public education and stigma reduction.