Exhibit 99.1 Media Contacts: Karissa Peer Investor Contacts: Jennifer Halchak (614) 314-8094 (201) 275-2711 Kate Vossen Renee McKnight (732) 675-8448 (551) 204-6129 Organon Reports Results for the First Quarter Ended March 31, 2024 • First quarter 2024 revenue of $1,622 million, up 5% on an as-reported basis and 7% at constant currency • First quarter 2024 diluted earnings per share of $0.78 and non-GAAP Adjusted diluted earnings per share of $1.22; both reported and non-GAAP Adjusted diluted earnings per s ...