Novo Nordisk has filed a lawsuit in federal court in New Jersey against Eli Lilly, alleging Eli Lilly’s advertising for its GLP-1 medicines Zepbound and Mounjaro is misleading and unfair. Novo says Lilly’s nationwide campaigns compare the effectiveness of Lilly’s products using higher-dose results with lower-dose results from Novo’s Wegovy and Ozempic, and that the comparisons are based on outdated clinical trial data that omit more recent information. Multiple outlets report that Novo argues the advertising improperly excludes at least the 7.2 mg dose of Wegovy, which Novo says was approved in March 2026 and is associated with greater average weight loss in the reported data. Novo also contends that there is no head-to-head trial comparing the highest approved doses of the two companies’ drugs, making some of Lilly’s comparative claims misleading.
Novo is seeking court relief that includes a permanent injunction to stop the challenged comparative advertisements and a requirement that Lilly run corrective advertising. The filings are described as part of a broader competitive effort by both companies for share in the GLP-1 obesity and type 2 diabetes market.
