Novo Nordisk filed a federal lawsuit in the U.S. District Court for the District of New Jersey on Tuesday, accusing Eli Lilly of deceptive advertising. The Danish pharmaceutical company alleges that its rival uses outdated clinical trial data in nationwide campaigns for the obesity drug Zepbound and the diabetes treatment Mounjaro to falsely suggest its treatments are superior to current high-dose versions of Novo Nordisk’s injections, such as Wegovy.
The Core Allegations Against Eli Lilly
The legal dispute centers on how Eli Lilly compares its weight-loss medication, Zepbound, against Novo Nordisk’s Wegovy. Novo Nordisk contends that Lilly’s marketing campaigns rely on comparative data from older studies that pitted Lilly’s highest doses against lower-strength versions of Novo’s injections. By omitting data from the recently approved 7.2-milligram dose of Wegovy, which entered the market in March, Novo claims these advertisements mislead consumers. The company argues that the campaigns leave consumers with the inevitable conclusion that Lilly's medicines are superior to Novo's, and that's not accurate, according to John Kuckelman, Novo’s group general counsel.
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The lawsuit asserts that these marketing practices violate federal and state laws, including the Lanham Act, a statute pharmaceutical companies have historically utilized to hold competitors accountable for deceptive advertising. The suit alleges that Lilly’s campaigns across television and social media are harmful because, unlike healthcare professionals who possess access to the full breadth of scientific evidence, consumers often rely on advertising to form their understanding of GLP-1 medications.
“Lilly’s advertising campaign deprives consumers of the truthful, current, and complete information they need to make informed decisions about their available treatment options.”
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Novo Nordisk court filing
The central point of contention is the efficacy of the 7.2-milligram dose of Wegovy. Novo Nordisk argues that this higher dose yields weight-loss results of approximately 47 pounds, which the company states is clinically consistent with the weight loss observed in Lilly’s most recent rigorous trials for Zepbound, which showed an average weight loss of about 48 pounds. However, the company alleges that Eli Lilly continues to run television commercials—which have received more than 700 million impressions since airing began around the end of April—claiming patients lose 50 pounds on average on Zepbound compared to 33 pounds on the 2.4-milligram dose of Wegovy.
John Kuckelman stated that while those comparisons might have held weight before the 7.2-milligram option was available, they are now inaccurate. 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, Kuckelman said. They have, we think, a legal obligation, but even more important, they have a responsibility to patients to share accurate information.
Novo Nordisk maintains that because no head-to-head clinical trials have compared the highest currently available doses of both drugs, Eli Lilly has no basis to make these comparative claims regarding superiority. While Lilly does include a footnote in its advertisements regarding the existence of higher-dose Wegovy, Novo characterizes that disclaimer as ambiguous, confusing, virtually illegible, and wholly inadequate because it fails to communicate that the drug is significantly more effective than the lower doses previously cited.
Legal Demands and Industry Context
Novo Nordisk is asking the court to permanently enjoin Eli Lilly from airing the current advertisements and require the company to issue corrective advertising. The lawsuit also seeks financial damages, though the specific amount remains undisclosed. The litigation follows a failed attempt to resolve the issue privately; Novo Nordisk reports that it sent a formal cease-and-desist request to Lilly in April, but the company refused to pull down or correct the advertisements.
Novo Nordisk Sues Eli Lilly Over Weight Loss Drug Advertisement
The lawsuit arrives as Novo Nordisk wages an aggressive battle to regain market share in the GLP-1 space. The company is actively positioning its new obesity pill, strategic price cuts, and the high-dose version of Wegovy to compete with Zepbound and Mounjaro. In recent years, Lilly’s medications have become preferred treatments among many providers and patients due to their high efficacy. Novo Nordisk contends that the high-dose Wegovy, which showed an average weight loss of around 19%, serves as a direct answer to that competition.
If Eli Lilly does not voluntarily remove the disputed advertisements, Novo Nordisk has signaled that it intends to seek a preliminary injunction in the coming days to force their removal while the case proceeds. Eli Lilly did not immediately respond to a request for comment.
