Molnupiravir
/api/v1/drug/molnupiravirBoxed warning
MANDATORY REQUIREMENTS FOR ADMINISTRATION OF LAGEVRIO UNDER EMERGENCY USE AUTHORIZATION In order to mitigate the risks of using this unapproved product under the EUA and to optimize the potential benefit of LAGEVRIO, the following steps are required. Use of LAGEVRIO under this EUA is limited to the following (all requirements must be met): Treatment of adults with mild-to-moderate COVID-19 who are at high risk for progression to severe COVID-19, including hospitalization or death and for whom alternative COVID-19 treatment options approved or authorized by FDA are not accessible or clinically appropriate [see Limitations of Authorized Use (1) ] . As the prescribing healthcare provider, review the information contained within the “Fact Sheet for Patients and Caregivers” with your patient or caregiver prior to the patient receiving LAGEVRIO. Healthcare providers must provide the patient/caregiver with an electronic or hard copy of the “Fact Sheet for Patients and Caregivers” prior to the patient receiving LAGEVRIO and must document that the patient/caregiver has been given an electronic or hard copy of the “Fact Sheet for Patients and Caregivers”. The prescribing healthcare providers must inform the patient/caregiver that: LAGEVRIO is an unapproved drug that is authorized for use under this Emergency Use Authorization.
Mechanism of action
Sourced from openFDAMolnupiravir is a prodrug with antiviral activity against SARS-CoV-2. It is metabolized to the cytidine nucleoside analogue, NHC which distributes into cells where NHC is phosphorylated to form the pharmacologically active ribonucleoside triphosphate (NHC-TP).
Contraindications
Sourced from openFDA- No contraindications have been identified based on the limited available data on the emergency use of LAGEVRIO authorized under this EUA.contraindicated
Dosage & administration
Sourced from openFDA2.1 Dosage for Emergency Use of LAGEVRIO in Adult Patients The dosage in adult patients is 800 mg (four 200 mg capsules) taken orally every 12 hours for 5 days, with or without food [see Clinical Pharmacology (12.3) ] . Take LAGEVRIO as soon as possible after a diagnosis of COVID-19 has been made, and within 5 days of symptom onset [see Emergency Use Authorization (1) and Clinical Studies (14) ] . Completion of the full 5-day treatment course and continued isolation in accordance with public health recommendations are important to maximize viral clearance and minimize transmission of SARS-CoV-2 [see Patient Counseling Information (17) ] . LAGEVRIO is not authorized for use for longer than 5 consecutive days because the safety and efficacy have not been established. If the patient misses a dose of LAGEVRIO within 10 hours of the time it is usually taken, the patient should take it as soon as possible and resume the normal dosing schedule. If the patient misses a dose by more than 10 hours, the patient should not take the missed dose and instead take the next dose at the regularly scheduled time. The patient should not double the dose to make up for a missed dose. Should a patient require hospitalization after starting treatment with LAGEVRIO, the patient may complete the full 5 day treatment course per the healthcare provider’s discretion. 2.2 Dosage Adjustments in Specific Populations No dosage adjustment is recommended based on renal or hepatic impairment or in geriatric patients [see Use in Specific Populations (8.5 , 8.6 , 8.7) ] .
Warnings & precautions
Sourced from openFDAThere are limited clinical data available for LAGEVRIO. Serious and unexpected adverse events may occur that have not been previously reported with LAGEVRIO use. 5.1 Embryo-Fetal Toxicity Based on findings from animal reproduction studies, LAGEVRIO may cause fetal harm when administered to pregnant individuals. There are no available human data on the use of LAGEVRIO in pregnant individuals to evaluate the risk of major birth defects, miscarriage or adverse maternal or fetal outcomes; therefore, LAGEVRIO is not recommended for use during pregnancy. When considering LAGEVRIO for a pregnant individual, the prescribing healthcare provider must communicate the known and potential benefits and the potential risks of using LAGEVRIO during pregnancy to the pregnant individual. LAGEVRIO is authorized to be prescribed to a pregnant individual only after the healthcare provider has determined that the benefits would outweigh the risks for that individual patient. If the decision is made to use LAGEVRIO during pregnancy, the prescribing healthcare provider must document that the known and potential benefits and the potential risks of using LAGEVRIO during pregnancy were communicated to the pregnant individual. Advise individuals of childbearing potential of the potential risk to a fetus and to use an effective method of contraception correctly and consistently, as applicable, during treatment with LAGEVRIO and for 4 days after the final dose [see Use in Specific Populations (8.1 , 8.3 and Nonclinical Toxicology (13.1) ] .
Adverse reactions
Sourced from openFDA6.1 Adverse Reactions from Clinical Studies The following adverse reactions have been observed in the clinical study of LAGEVRIO that supported the EUA. The adverse reaction rates observed in these clinical trials cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Additional adverse events associated with LAGEVRIO may become apparent with more widespread use. Overall, more than 900 subjects have been exposed to LAGEVRIO 800 mg twice daily in clinical trials. The safety assessment of LAGEVRIO is primarily based on an analysis from subjects followed through Day 29 in the Phase 3 study in non-hospitalized subjects with COVID-19 (MOVe-OUT) [see Clinical Studies (14) ] . The safety of LAGEVRIO was evaluated based on an analysis of a Phase 3 double-blind trial (MOVe-OUT) in which 1,411 non-hospitalized subjects with COVID-19 were randomized and treated with LAGEVRIO (N=710) or placebo (N=701) for up to 5 days. Adverse events were those reported while subjects were on study intervention or within 14 days of study intervention completion/discontinuation. Discontinuation of study intervention due to an adverse event occurred in 1% of subjects receiving LAGEVRIO and 3% of subjects receiving placebo. Serious adverse events occurred in 7% of subjects receiving LAGEVRIO and 10% receiving placebo; most serious adverse events were COVID-19 related. Adverse events leading to death occurred in 2 (<1%) subjects receiving LAGEVRIO and 12 (2%) of subjects receiving placebo.
Use in specific populations
Sourced from openFDA8.1 Pregnancy Pregnancy Registry There is a pregnancy registry that monitors pregnancy outcomes in individuals exposed to LAGEVRIO during pregnancy. The prescribing healthcare provider must document that a pregnant individual was made aware of the pregnancy registry at https://covid-pr.pregistry.com or 1-800-616-3791. Pregnant individuals exposed to LAGEVRIO or their healthcare providers can also report the exposure by contacting Merck Sharp & Dohme LLC, Rahway, NJ USA at 1-877-888-4231. Risk Summary Based on animal data, LAGEVRIO may cause fetal harm when administered to pregnant individuals. There are no available human data on the use of LAGEVRIO in pregnant individuals to evaluate the risk of major birth defects, miscarriage or adverse maternal or fetal outcomes; therefore, LAGEVRIO is not recommended during pregnancy [see Box and Warnings and Precautions (5.1) ] . In an animal reproduction study, oral administration of molnupiravir to pregnant rats during the period of organogenesis resulted in embryofetal lethality and teratogenicity at 8 times the human NHC (N4-hydroxycytidine) exposures at the recommended human dose (RHD) and reduced fetal growth at ≥ 3 times the human NHC exposure at the RHD.
Pharmacokinetics
Sourced from openFDA- Metabolism
- Molnupiravir is a 5´-isobutyrate prodrug of NHC that is hydrolyzed during or after absorption. NHC, the primary circulating analyte, is taken up by cells and anabolized to NHC-TP.
Overdosage
Sourced from openFDAThere is no human experience of overdosage with LAGEVRIO. Treatment of overdose with LAGEVRIO should consist of general supportive measures including the monitoring of the clinical status of the patient. Hemodialysis is not expected to result in effective elimination of NHC.
FAERS reports
- 1Product Use Issue71014%
- 2No Adverse Event63012%
- 3Covid-194819.3%
- 4Wrong Technique In Product Usage Process3947.6%
- 5Product Use In Unapproved Indication3116.0%
- 6Diarrhoea2705.2%
- 7Product Use Complaint2134.1%
- 8Rash2104.1%
- 9Accidental Underdose2074.0%
- 10Nausea1913.7%
- 11Underdose1883.6%
- 12Drug Ineffective1823.5%
- 13Accidental Overdose1522.9%
- 14Vomiting1472.8%
- 15Inappropriate Schedule Of Product Administration1422.8%
Clinical trials
The 10 most recently updated of 31 ClinicalTrials.gov registrations naming Molnupiravir as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.
- A Clinical Study of Molnupiravir to Prevent Severe Illness From Coronavirus Disease 2019 (COVID-19) in People Who Are High Risk (MK-4482-023)Recruiting · Phase 3 · Interventional · 3,082 enrolled · Merck Sharp & Dohme LLCNCT06667700updated 2026-06-12
- AGILE (Early Phase Platform Trial for COVID-19)Recruiting · Phase 1 · Phase 2 · Interventional · 600 enrolled · University of LiverpoolNCT04746183updated 2026-06-01
- Adaptive Dengue Antiviral Platform TrialRecruiting · Phase 2 · Interventional · 500 enrolled · Oxford University Clinical Research Unit, VietnamNCT06551844updated 2026-04-30
- Randomised Evaluation of COVID-19 TherapyRecruiting · Phase 3 · Interventional · 70,000 enrolled · University of OxfordNCT04381936updated 2026-04-21
- A Clinical Study of MK-4482 in Chinese Healthy Male Participants (MK-4482-009)Completed · Phase 1 · Interventional · 16 enrolled · Merck Sharp & Dohme LLCNCT06816030updated 2026-04-16
- A Phase 2 Trial Comparing Antiviral Treatments in Early Symptomatic InfluenzaRecruiting · Phase 2 · Interventional · 3,000 enrolled · University of OxfordNCT05648448updated 2026-04-14
- Finding Treatments for COVID-19: A Trial of Antiviral Pharmacodynamics in Early Symptomatic COVID-19 (PLATCOV)Recruiting · Phase 2 · Interventional · 3,800 enrolled · University of OxfordNCT05041907updated 2026-02-19
- Clinical Outcomes and Pharmacotherapy Effectiveness in the VA Health Care System (COPE-VA)Recruiting · Observational · 400,000 enrolled · VA Office of Research and DevelopmentNCT06160128updated 2026-02-10
- TURN-COVID Biobank: The Dutch Cohort Study for the Evaluation of the Use of Neutralizing Monoclonal Antibodies and Other Antiviral Agents Against SARS-CoV-2Completed · Observational · 1,178 enrolled · Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)NCT05195060updated 2025-12-16
- COVID-19 International Drug Pregnancy RegistryRecruiting · Observational · 2,000 enrolled · PregistryNCT05013632updated 2025-09-26
Frequently asked questions
- How does Molnupiravir work?
- Molnupiravir is a prodrug with antiviral activity against SARS-CoV-2. It is metabolized to the cytidine nucleoside analogue, NHC which distributes into cells where NHC is phosphorylated to form the pharmacologically active ribonucleoside triphosphate (NHC-TP).
- What class of drug is Molnupiravir?
- Molnupiravir is classified as Nucleosides and nucleotides excl. reverse transcriptase inhibitors, Nucleic Acid Replication Alteration.
- What are the brand names for Molnupiravir?
- Molnupiravir is marketed under brand names including Lagevrio.
- What are the contraindications for Molnupiravir?
- Molnupiravir labeling lists contraindications including: No contraindications have been identified based on the limited available data on the emergency use of LAGEVRIO authorized under this EUA.. Always consult the full prescribing information and a clinician.
molnupiravir is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.