What specific false advertising claims did Novo Nordisk allege against Eli Lilly in its lawsuit?

Novo Nordisk alleged that Eli Lilly's nationwide advertising campaigns for Zepbound and Mounjaro violated the Lanham Act and state false advertising laws by comparing the highest approved doses of Lilly's medicines to lower, outdated doses of Novo's Wegovy and Ozempic—while omitting Novo's newly approved higher-dose Wegovy (7.2 mg)—making the ads 'maliciously and deceptively false' because they cited 'outdated clinical trials' that did not reflect current dosing options.

How did Eli Lilly respond to Novo Nordisk's lawsuit and what evidence did it cite in defense of its advertising?

Eli Lilly stated it 'stands firmly behind its ads,' asserting they are based on results from its completed 2024 SURMOUNT-5 trial, which compared patients on 10 mg or 15 mg of Zepbound to those on 1.7 mg or 2.4 mg of Wegovy—the doses approved at the time of the trial—and emphasized that Novo is attempting to suppress scientific communication rather than compete on product merits, vowing to 'defend against this lawsuit vigorously.'

Novo Nordisk Sues Eli Lilly Over Misleading Ads in Weight-Loss Drug Battle

Jul 21, 2026

Novo Nordisk sued Eli Lilly in U.S. court, alleging false advertising claims comparing their weight-loss drugs Zepbound and Wegovy. The lawsuit underscores fierce competition in the obesity market, resulting in a 2% drop for Novo shares.

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