Novo Nordisk wrote in a press release that it is suing GLP-1 rival Eli Lilly in federal court in New Jersey, alleging nationwide "deceptive advertising" for Zepbound and Mounjaro. The company claims Lilly misleads consumers by comparing Lilly's highest doses with lower doses of Novo's Wegovy and Ozempic. Novo claims Lilly's Zepbound advertising campaign relies on outdated studies that exclude the 7.2-milligram dose of Wegovy, approved in March 2026, which produced an average weight loss of about 19%. What Novo seeks:Through this action, Novo Nordisk is seeking a permanent injunction requiring Lilly to pull its misleading comparative advertising across all platforms and to conduct a corrective advertising campaign. Novo entered the obesity market first with Wegovy, but Lilly has since overtaken its rival with Zepbound and now leads in sales.