It turns on battle of obesityThe billion-dollar challenge for control of the slimming drug market is moving from pharmacies to courtrooms. Novo Nordisk has initiated a federal lawsuit in the United States against Eli Lilly, accusing the rival of having promoted Zepbound and Mounjaro through false and misleading advertising campaigns.
The action was filed in the United States District Court for New Jersey and alleges violations of federal and state laws on misleading advertising and unfair competition, including the Lanham Act. At the heart of the dispute are above all the comparisons used by Lilly to support the superiority of its drugs over Wegovy and Ozempic.
Novo Nordisk disputes comparisons used in commercials
According to Novo Nordisk, Eli Lilly's national direct-to-consumer campaigns were built by selecting clinical studies now out of dateThe advertisements allegedly compare the highest available doses of Zepbound and Mounjaro with lower doses of competing products, without taking into account the newer, higher dosage formulations of Wegovy and Ozempic. The Danish pharmaceutical company claims that the advertisements have thus created theimpressed and Zepbound guarantees weight loss sharply superior to Wegovy and that Mounjaro is more effective than Ozempic in blood sugar control.
In the complaint, Novo claims that the advertisements were “intentionally and deceptively false”, because they are based on trials prior to the approval of the most recent doses of its drugs. The main reference is to the new 7,2-milligram injectable formulation of Wegovy, approved in the United States in March 2026.
According to the data cited by the company, studies using the highest doses showed an average weight loss of approximately 48 pounds for Zepbound and approximately 47 pounds for Wegovy. Novo emphasizes, however, that no head-to-head study has ever been conducted comparing the highest approved doses of the two treatments.
The formal notice and the request to withdraw the advertisements
The legal action comes after a formal notice sent by Novo Nordisk to Eli Lilly in April. The Danish company had asked its competitor to withdraw or modify in a substantial manner the contested campaigns, but the request did not produce the desired results. According to John F. Kuckelman, head of legal for the Novo Nordisk group, Lilly subsequently inserted a clarification deemed insufficientThe campaign's impact, Novo claims, was particularly large, with over 700 million consumer views after the changes introduced at the end of April alone.
- spot They were allegedly distributed during highly watched sports broadcasts and through social media platforms like TikTok and Facebook. Novo believes that any background warnings would not be sufficient to correct the ads' main message. "As new and more effective treatment options emerge, people deserve accurate information that reflects the latest scientific evidence and helps them make informed treatment decisions," Kuckelman said. "Healthcare companies have a responsibility to keep their public statements accurate and up-to-date. Ineffective fine print does not correct the misleading impression created by large national campaigns," he specified.
Novo demands a halt to the ads and compensation
With the cause, Novo Nordisk asks the court to permanently prevent Eli Lilly from continuing to broadcast the contested advertisements.The company also wants the competitor to launch a corrective campaign to clarify for consumers the terms of comparisons between different medicines.
The Danish company also announced its intention to apply for apreliminary injunctionand if Lilly does not voluntarily withdraw the ads. The demands also include financial compensation, including the profits Novo believes its rival earned from the advertising campaigns. The total amount was not disclosed.
Eli Lilly did not immediately provide a public response to the allegations in the lawsuit.
A billion-dollar game for the anti-obesity drug market
The legal dispute represents a new chapter of the competition between the two main players in the market for GLP-1 drugs against diabetes and obesity. sector which, according to estimates cited by analysts, could exceed $ 100 billion by 2030.
Novo Nordisk was the first to arrive on the market with wegovy, but subsequently lost ground to Zepbound in the United States. The Danish company is now trying to regain market share by launching the oral version of Wegovy, a more aggressive pricing strategy, and the introduction of a new high-dose injectable formulation. Eli Lilly, for its part, can count on the Zepbound growth in the treatment of obesity and Mounjaro against diabetes, as well as on entering the oral drugs segment.
The competition between the two groups is no longer just about clinical efficacy, prices, and production capacity. With the lawsuit filed in New Jersey, the battle to win over doctors and patients is now also being waged on the accuracy of the information used to advertise the drugs.
