On Dec. 23, 2021, Merck and Ridgeback Biotherapeutics announced that the U.S. Food and Drug Administration (FDA) had granted Emergency Use Authorization (EUA) for molnupiravir, an investigational oral antiviral.

Molnupiravir had not been approved, but had been authorized for emergency use by the FDA under an EUA to treat mild to moderate coronavirus disease 2019 (COVID-19) in adults with positive results of direct SARS-CoV-2 viral testing, and who are at high risk for progression to severe COVID-19, including hospitalization or death, and for whom alternative COVID-19 treatment options authorized by the FDA are not accessible or clinically appropriate.

Molnupiravir was not authorized for use in patients who are less than 18 years of age, for initiation of treatment in patients hospitalized due to COVID-19, for use for longer than five consecutive days, or for pre-exposure or post-exposure prophylaxis for prevention of COVID-19.