Novo Nordisk has filed a lawsuit against Eli Lilly, alleging false advertising and deceptive marketing for Zepbound and Mounjaro treatments.

The lawsuit, filed in federal court Tuesday, accuses Eli Lilly of using outdated data in advertising campaigns.

The lawsuit follows a cease-and-desist request and argues Lilly is using “deceptive” ads to claim its GLP-1 products are broadly superior to Novo’s medicines. Lilly countered that…