Novo Nordisk Sues Eli Lilly Over GLP‑1 Ads as Lilly Pulls Ahead Commercially

Overview

• Novo Nordisk filed a federal lawsuit on July 21 accusing Eli Lilly of false advertising for national TV and digital campaigns and moved on July 24 for a preliminary injunction to stop those ads.
• The complaint says Lilly’s commercials compare Lilly’s highest approved tirzepatide doses to older, lower-dose semaglutide data and omit Novo’s newer higher-dose Wegovy formulations, and it asks for corrective advertising and damages.
• Eli Lilly says the ads are truthful, rely on the SURMOUNT-5 head-to-head trial that compared tirzepatide with semaglutide, and that the company will defend the campaigns vigorously in court.
• Recent financial and market data show Lilly with stronger near-term U.S. momentum and raised 2026 guidance while Novo’s headline growth was aided by a DKK 4.2 billion 340B accounting reversal and showed weaker adjusted sales.
• A court decision on the legality of dose-specific comparisons or any ordered corrective ads could shift patient perceptions, prescriber choice and payer coverage in the multibillion-dollar GLP-1 weight-loss market.