The lawsuit comes as pharmaceutical heavyweights Novo and Eli Lilly are locked in a battle to dominate the fast-growing weight-loss drug industry, especially in the United States, which analysts have estimated could be worth more than $100 billion by 2030.

Novo Nordisk claimed that its main competitor in the weight-loss drug business had committed “multiple violations” of federal and state laws on false advertising and unfair competition, through its nationwide advertising campaigns.

The company said Eli Lilly’s current campaigns “intentionally” selected outdated studies that compared higher doses of Lilly with lower doses of Novo Nordisk’s drugs.

He said the ads “misleadingly” portrayed Eli Lilly’s products as superior, but obscured or omitted “critical clinical context.”

The products that were incorrectly compared, according to Novo, were Mounjaro vs. Ozempic and Zepbound vs Wegovy.

“As new and more effective treatment options become available, people deserve accurate information that reflects the latest scientific evidence and helps them make informed care decisions,” said John F. Kuckelman, senior vice president and group general counsel, Novo Nordisk.

“Healthcare companies have a responsibility to keep their public claims accurate and up-to-date; ineffective, fine-print disclaimers do not address the misleading impression created by major national campaigns,” he said.

Novo said it was seeking a court order requiring Eli Lilly to withdraw its ads and instead run what it called a “corrective advertising campaign.”

He added that if Eli Lilly did not voluntarily remove the ads, he would file a motion in the coming days seeking a preliminary injunction to block them.

But Eli Lilly accused Novo of asking the court to prevent the company from communicating the results of a comparative trial that it said was “robustly designed” and “the gold standard.”