According to reports from Reuters, Novo Nordisk filed a lawsuit in U.S. District Court in New Jersey on July 21 against rival Eli Lilly. The Danish pharmaceutical company is alleging that Lilly engaged in false advertising for claiming its weight-loss medicines outperform Novo's products. Novo seeks to block Lilly's advertising campaigns and requires corrective measures to address the alleged violations. As per USA TODAY, Novo claims the ads are 'deliberately simple and deliberately false' because they compare the highest doses of Lilly's medicines to lower doses of Novo's products. John Kuckelman, Novo's senior vice president and group general counsel, told USA TODAY that the lawsuit addresses 'a nationwide pattern of deceptive advertising, where campaigns are misleading people with obesity and diabetes by comparing the highest doses of Lilly's medicines with lower doses of Novo's medicines.' Eli Lilly did not immediately respond to a request for comment.
As reported by Reuters, Novo alleges that Lilly violated federal and state false advertising and unfair competition laws, including the Lanham Act, through nationwide advertising campaigns. The lawsuit specifically targets Lilly's obesity drug Zepbound and diabetes treatment Mounjaro. According to USA TODAY, Novo claims Lilly's ads are 'deliberately false' because they tout 'outdated clinical trials that compare the highest doses of the Lilly medicines to lower doses of Novo Nordisk's medicines.' The company alleges the ads present results as 'proof of broad, product-level superiority while burying or omitting critical clinical context.' A Lilly television commercial compared the companies' weight-loss drugs, stating that people using Lilly's Zepbound lost an average of 50 pounds compared to an average of 33 pounds for Wegovy's 2.4 milligram dose, though the commercial did not share results from a clinical trial showing patients on a higher dose of Wegovy lost an average of 47 pounds. The lawsuit also claims Lilly used the 'same misleading approach' in ads comparing the companies' diabetes drugs, comparing higher-dose versions of Mounjaro to lower-dose versions of Ozempic, even when a higher-dose version of Ozempic was available. John Kuckelman, Novo's senior vice president and group general counsel, told USA TODAY that 'What has brought us to this moment is what we now see as a nationwide pattern, by Lilly, of deceptive advertising. They are intentionally confusing consumers.'
According to USA TODAY, Novo claims Lilly's false advertising has 'diverted patient demand and prescriptions from Novo Nordisk's medicines to Lilly's medicines.' The lawsuit comes as the two pharmaceutical companies are engaged in an intense battle over the market for popular GLP-1 weight-loss drugs, which are mainly prescribed to treat obesity and Type 2 diabetes. While Novo was first on the market with its anti-obesity medication Wegovy, Lilly's sales for weight-loss drug Zepbound have surged significantly. Zepbound's sales reached nearly $4.2 billion during the first three months of 2026, representing an 80% increase from the year before. Analysts expect the weight-loss sector to generate about $100 billion in annual sales in the next decade, with more than a half dozen pharmaceutical companies developing new versions of weight-loss drugs in the competitive markets. Both companies could benefit from millions of older adults who now might qualify for popular GLP-1 weight loss drugs under a new Medicare pilot program. The suit alleges that Lilly's Zepbound TV commercial has received more than 700 million impressions since it began airing around the end of April, demonstrating the scale of competitive harm to Novo.
As reported by Reuters, Novo isn't asking Lilly to stop selling the blockbuster weight-loss and diabetes medications. Rather, Novo is asking a judge to issue a permanent order requiring Lilly to pull its comparison ads across all platforms. The company also wants the court to order Lilly to conduct a 'corrective advertising campaign.' Novo is also seeking financial damages, though the exact amount remains unclear. According to USA TODAY, Novo has warned Lilly that if the ads are not removed voluntarily, it plans to seek a preliminary injunction in the coming days to block them immediately while the case proceeds. John Kuckelman, Novo's senior vice president and group general counsel, told USA TODAY that the lawsuit addresses 'a nationwide pattern of deceptive advertising, where campaigns are misleading people with obesity and diabetes by comparing the highest doses of Lilly's medicines with lower doses of Novo's medicines.' Eli Lilly did not immediately respond to a request for comment.
The lawsuit comes as the weight-loss drug market faces significant regulatory changes that could benefit both companies. On July 1, the Centers for Medicare and Medicaid Services launched the Medicare GLP-1 Bridge program for enrollees who qualify for prescription weight-loss medication based on height, weight and other criteria. Medicare enrollees must pay a monthly $50 copay, and Medicare will cover the rest. Both companies could benefit from millions of older adults who now might qualify for popular GLP-1 weight loss drugs under this new program. The Food and Drug Administration approved the higher, 7.2-milligram dose of Wegovy in March 2026, which showed an average weight loss of around 19%. Novo alleges that Lilly acknowledges the existence of that high-dose Wegovy in a 'small footnote,' but called it 'ambiguous, confusing, virtually illegible, and wholly inadequate,' as it does not communicate that it is significantly more effective than the lower doses of the drug. The suit adds that no head-to-head trials have compared the highest doses of Wegovy and Zepbound currently available on the market, so Lilly has 'no basis to make these comparative claims' that its drugs are more effective. John Kuckelman, Novo's senior vice president and group general counsel, told USA TODAY that 'While it may have been accurate to say that before 7.2 milligrams became available for Wegovy, it is no longer accurate to say that,' emphasizing Lilly's legal and ethical responsibility to share accurate information with patients.
