The news: Novo failed to temporarily block Eli Lilly’s direct-to-consumer (D2C) ads, which Novo alleges misleadingly portray Zepbound and Mounjaro as more effective than Wegovy and Ozempic. A federal judge ruled that Novo failed to show irreparable harm to its sales, goodwill, or clinical reputation from the ads. He did not rule on whether the ads were misleading, and the broader false advertising lawsuit continues.

Zooming out: Novo sued Lilly in July, alleging Lily’s two ad campaigns selectively presented clinical data by comparing lower doses of Novo's drugs with higher doses of Lilly's to make Lilly's treatments appear more effective.

Why it matters: Lilly's ads can keep running while Novo challenges their accuracy in court, so the disputed claims will stay in circulation during a heated GLP-1 advertising battle. Both companies pour money into TV, where those claims have appeared. In Q3, Lilly spent $53 million promoting Zepbound on linear and streaming TV, while Novo spent $81 million on Wegovy, per iSpot data shared with EMARKETER. That spending put both brands among the quarter’s top 10 pharma advertisers.

Novo trails Lilly in sales of the injectable GLP-1 drugs at the center of the dispute, and challenging its rival’s advertising claims was likely an attempt to regain lost ground. In Q2, Lilly’s type 2 diabetes drug Mounjaro generated $9.9 billion, compared with $4.9 billion for Novo’s Ozempic. Lilly’s obesity drug Zepbound also outsold injectable Wegovy in Q2 with $4.9 billion in sales compared with $3.0 billion. High volume prescribers favor Zepbound for clinical efficacy, label advantages and enhanced patient access through direct‑to‑patient programs, per a January IQVIA study. Novo has an early lead in the newer oral obesity drug market, but its pill sales remain small compared with Lilly’s injectable revenues and haven’t made a meaningful dent in the sales gap.

Implications for pharma marketers: Claiming that one drug works better than a competitor's can be a compelling ad, but it also can invite legal challenges over how clinical evidence is presented.

The Novo-Lilly dispute also shows how ads comparing specific doses can leave patients with a broader impression that one drug works better overall. That impression could shape what patients expect from treatment and what they ask their providers about, even though greater average weight loss with one drug doesn’t guarantee better results.

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