US judge denies Novo Nordisk bid to block Eli Lilly's Zepbound and Mounjaro ads

Judge Zahid Quraishi of the US District Court for the District of New Jersey in Trenton ruled on Monday that Novo Nordisk had failed to show Lilly's ads threatened its sales, damaged its goodwill or caused lasting harm to its clinical reputation.

The ruling keeps Lilly's ads running in the US, one of the few countries that allows direct-to-consumer advertising of prescription medicines. Patients comparing Wegovy and Zepbound will keep seeing the claim that Zepbound users lost an average of 50 pounds (23 kg) against 33 pounds (15 kg) for Wegovy, with a written disclaimer on screen. The judge said money damages could compensate Novo for any "nontrivial harm."

The judge's reasoning

In a 25-page decision, Quraishi called Novo's case for a preliminary injunction "less than persuasive" based on a "very preliminary record." He said Novo's claim of irreparable harm was "inadequate to warrant the extraordinary relief it seeks." He found Lilly's ads had at most a negligible market impact between April and July, with prescriptions for Novo's products remaining stable in that period.

Quraishi also turned Novo's own marketing history against it. He wrote that Novo "engaged in a nearly identical advertising strategy and now complains because it is being subjected to similar conduct." He said Novo had run similar ads comparing Ozempic with Lilly's older Trulicity, pharmaphorum reported. The ruling followed a two-day hearing in late August, Reuters reported.

What the ads say

Novo sued in July, alleging Lilly's campaigns violated federal and state false-advertising and unfair-competition laws. The suit said Lilly compared its highest doses of Zepbound and Mounjaro with lower doses of Wegovy and Ozempic. For Mounjaro, Novo said the ads used the 15 mg dose against Ozempic's 1 mg rather than its highest approved 2 mg dose. Novo also argued that Lilly ignored the 72-week STEP UP trial of a 7.2 mg Wegovy dose, the highest strength the FDA had approved as of March 2026. Novo said Lilly leaned instead on studies using Wegovy at 1.7 mg and 2.4 mg.

Lilly answered that its campaigns rest on SURMOUNT-5, which it calls the only randomized head-to-head trial of tirzepatide and semaglutide for weight management. "We will continue to focus on the science and defend against this lawsuit vigorously," a Lilly spokesperson said. Novo's senior vice president and group general counsel, John F. Kuckelman, said in a statement that "ineffective, fine-print disclaimers do not fix the misleading impression created by major national campaigns."

Why the fight matters

Court documents put Novo's combined 2025 sales at about $32 billion from obesity medicines and Ozempic, which is licensed for diabetes. Lilly is the larger business by revenue: $65.2 billion in 2025 and a profit of $20.6 billion, against Novo's $47 billion and $15.4 billion. Lilly's revenue grew 45 percent that year. Novo's grew 6 percent.

Both are chasing a market that Bloomberg Intelligence estimates could reach $120 billion a year by 2030. Goldman Sachs forecast $114 billion by 2030 in July, and analysts cited by Reuters put the US market alone above $100 billion by the end of the decade. Novo once dominated the category with Wegovy. Lilly caught up with Zepbound and now leads in sales.

BMO analyst Evan Seigerman said the suit looked like an effort by Novo to change how the public compares the two companies' medicines, Reuters reported.

What happens next

Novo said the ruling did not decide whether Lilly's advertising is false and misleading. "Everyone deserves clear, accurate and up-to-date information when making decisions about their health," a Novo spokesperson said. Novo is seeking a permanent injunction that would force Lilly to pull the campaigns and run corrective advertising. It had asked for the earlier order on an expedited basis, saying patients needed an "accurate, complete picture" of the available treatments.

Lilly said it was pleased with the decision. "Our focus has been and continues to be on the millions of people living with obesity, type 2 diabetes, and other chronic diseases," the Indianapolis-based company said.