Novo Nordisk filed suit against Eli Lilly, accusing its rival of false advertising and unfair competition over their respective obesity and diabetes medications. The lawsuit, filed in the U.S. District Court for the District of New Jersey, seeks to permanently halt Lilly's ad campaigns and compel corrective advertising.
Novo Nordisk objects to national advertisements it says rely on outdated clinical trials. The campaigns compare the highest doses of Lilly's drugs—Zepbound and Mounjaro—to lower doses of Novo's injections, including Wegovy.
The ads exclude data from Novo's high-dose Wegovy, approved and on the market since March. That formulation produces average weight loss of around 19 percent, putting it closer to Lilly's results.
John Kuckelman, Novo's group general counsel, said Lilly refused to remove or correct specific ads after receiving a cease-and-desist from Novo in April. He said the ads lead consumers to believe Lilly's medicines are superior, which is not accurate.
Novo's complaint brings federal and state unfair competition and false advertising claims, including under the Lanham Act. The company also seeks unspecified financial damages and has told Lilly it plans to pursue a preliminary injunction in the coming days to block the ads while the case proceeds.
Eli Lilly said it stands behind its advertising, calling its campaigns grounded in a head-to-head clinical trial that directly compares Zepbound to Wegovy—the only such study of its kind. Lilly said its advertising is truthful and transparent and that it will defend against the lawsuit vigorously.
The legal dispute comes as Novo Nordisk fights to reclaim market share in the GLP-1 sector. The company is deploying its new high-dose Wegovy, an obesity pill and price cuts to compete with Lilly's Zepbound and Mounjaro, which have become preferred treatments among many providers and patients.
