Novo Nordisk said it has filed a lawsuit in U.S. federal court against Eli Lilly and Lilly USA, alleging that nationwide advertising for Zepbound and Mounjaro is false, misleading and unfairly competitive because it compares Lilly’s highest doses to lower doses of Novo’s medicines while leaving out newer and more effective options.
The complaint, filed in the U.S. District Court for the District of New Jersey, says Lilly’s campaigns mislead consumers living with obesity and type 2 diabetes by omitting important scientific context about Wegovy and Ozempic. Novo said the ads create the impression that Lilly’s medicines are superior, including by failing to mention Wegovy’s 7.2 mg injectable dose, which the company says was approved by the FDA in March 2026 and produced an average weight loss of about 19% in the STEP UP trial.
Novo said it previously asked Lilly to withdraw or correct the ads, but Lilly declined to do so. The company is seeking a permanent injunction to stop the comparative advertising across platforms and a corrective advertising campaign. It also said it may seek a preliminary injunction to immediately halt the ads if needed.
According to Novo, the challenged campaigns compare Zepbound’s 10 mg and 15 mg doses with Wegovy’s 1.7 mg and 2.4 mg doses, and compare Mounjaro’s 15 mg dose with Ozempic’s 1 mg dose, despite a higher 2 mg maintenance dose being available for Ozempic. Novo argued that these comparisons are unfair because there are no head-to-head trials between the highest doses of the medicines.
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