Novo Nordisk, the company behind Ozempic and Wegovy, has filed a lawsuit accusing Eli Lilly of false advertising by claiming its weight-loss drugs are superior. The Danish pharma giant filed the suit in the US on Tuesday, arguing that Eli Lilly's ad campaigns for Mounjaro and Zepbound create a misleading impression by comparing its highest approved doses against lower doses of Novo's drugs, while omitting newer, higher-dose options. Eli Lilly fired back, saying its ads are 'truthful, transparent, and grounded in the most direct scientific evidence available,' and vowed to defend itself vigorously. The legal showdown comes as both companies vie for dominance in the weight-loss drug market, which analysts estimate could exceed $100bn by 2030. Novo is seeking a court order to force Eli Lilly to pull the ads and run a 'corrective advertising campaign,' threatening a preliminary injunction if they don't comply. Eli Lilly accuses Novo of trying to suppress the results of a comparison trial it describes as 'robustly designed' and 'the gold standard.'