Novo Nordisk has filed a motion for a preliminary injunction in the U.S. District Court for the District of New Jersey, asking a judge to immediately stop Eli Lilly from running its current U.S. advertising campaigns for obesity and diabetes drugs.

The motion, filed Friday, is the latest step in a legal dispute Novo Nordisk began on Tuesday when it sued Lilly over advertisements for the obesity drug Zepbound and the diabetes treatment Mounjaro. Novo had warned when the lawsuit was filed that it would seek emergency court intervention if Lilly did not voluntarily withdraw the disputed campaigns. Lilly did not pull the ads.

Novo Nordisk alleges that Lilly’s advertising uses misleading dose comparisons between Lilly’s products and Novo’s GLP-1 drugs Wegovy and Ozempic. According to Novo, the campaigns compare the highest approved doses of Zepbound and Mounjaro against lower doses of Wegovy and Ozempic, while failing to disclose that Novo offers newer, higher-dose versions of its drugs.

Novo says those higher-dose versions produce greater weight-loss results, and that omitting them from the comparisons misleads consumers. The Danish drugmaker is alleging violations of false advertising and unfair competition laws. The claims center on how competing prescription medicines are presented to patients and physicians in U.S. direct-to-consumer advertising, a high-stakes channel in a category where clinical results, approved dosing and label language are closely scrutinized.

NVO stock was down 0.02% on the day, while LLY gained 1.97%.

What Novo Nordisk Is Seeking

Novo Nordisk is asking the court to temporarily halt the challenged advertisements while the lawsuit proceeds. It is also seeking a permanent injunction that would require Lilly to withdraw the campaigns and run corrective advertising.

A preliminary injunction, if granted, would stop the ads before the court reaches a final decision in the case. Such orders are generally considered a significant procedural step because the party requesting them must persuade the court that immediate relief is warranted before the underlying claims are fully resolved.

Lilly’s Response

Eli Lilly denied wrongdoing when Novo filed the lawsuit on Tuesday. The company said it stood by its advertising and would vigorously defend itself.

Lilly had not responded to a request for comment by the time of publication Friday.

The dispute comes as Novo Nordisk and Eli Lilly compete in the GLP-1 drug market, where analysts project U.S. sales could exceed $100 billion by the end of the decade. Wegovy and Zepbound are approved for chronic weight management, while Ozempic and Mounjaro are approved for type 2 diabetes, placing the companies’ brands at the center of fast-growing obesity and metabolic-disease treatment markets. Novo’s case is now before the District of New Jersey, with the preliminary injunction motion serving as the next key procedural step in the lawsuit.