The intense rivalry between Novo Nordisk and Eli Lilly in the market for GLP-1 agonist-based therapies for obesity and type 2 diabetes has spilt over into the courts. Novo Nordisk filed a lawsuit today accusing Lilly of a "nationwide pattern of deceptive advertising" that it claims is designed to confuse the public and cast its medicines in a poor light. It claims that ads for the two drugs misrepresent its rival Wegovy and Ozempic therapies, containing GLP-1 agonist semaglutide, as they omit relevant information about their efficacy. The legal action comes as Novo Nordisk has been losing ground to Lilly in the GLP-1 market, with growth rates for injectable Wegovy and Ozempic both slowing down as Zepbound and Mounjaro romp away. Novo Nordisk said it is seeking a permanent injunction on the campaigns, and wants Lilly to run another correcting its claims.