What are the side effects of Lagevrio (Molnupiravir)?

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Last updated: February 7, 2025 • View editorial policy

From the Guidelines

Lagevrio (Molnupiravir) is associated with several potential side effects, including toxicity, carcinogenesis, and genotoxicity.

Side Effects

  • Toxicity: The drug has been shown to have potential toxicity concerns, particularly in children, pregnant or breastfeeding individuals, and younger adults 1, 2.
  • Carcinogenesis: In vitro and animal studies have suggested the possibility of carcinogenesis, although no human data with long-term follow-up are available 1.
  • Genotoxicity: There is uncertainty regarding the long-term risk of genotoxicity, particularly in younger patients, and the potential for temporary genotoxic effects on sperm cell production in men 1, 2.
  • Embryo-fetal lethality and teratogenicity: Molnupiravir has been shown to cause embryo-fetal lethality and teratogenicity in animal studies, and its use is not recommended in pregnant or breastfeeding individuals 2.

Special Considerations

  • Children: Molnupiravir should not be used in children due to evidence of impact on growth plate thickness and decreased bone formation in animal studies 2.
  • Pregnancy and breastfeeding: The drug should not be used in pregnant or breastfeeding individuals, and people who might become pregnant should be counselled regarding reducing the risk of conception during treatment and for at least four days after the last dose of molnupiravir 2.
  • Men planning to conceive: Men planning to conceive should be oriented on the potential for temporary genotoxic effects on sperm cell production, and should use reliable contraception during treatment and for at least three months after the last dose of molnupiravir 2.

The FDA Drug Labels for molnupiravir (PO) do not address this question.

From the Research

Side Effects of Lagevrio (Molnupiravir)

The side effects of Lagevrio (Molnupiravir) are as follows:

  • Nausea
  • Diarrhea
  • Headache
  • Vomiting

Details of Side Effects

These side effects were observed in clinical trials where patients received a daily dose of 1600 mg Molnupiravir for 5 days 3. The studies also showed that Molnupiravir was well tolerated and safe without any major adverse events on short-term use 3, 4, 5.

Patient Response to Molnupiravir

In one study, patients who received Molnupiravir demonstrated early clinical improvement, no need for hospitalization, and a low rate of adverse events 5. Another study found that Molnupiravir was associated with greater mean reductions from baseline in SARS-CoV-2 RNA than placebo, and no participant had infectious SARS-CoV-2 by day 3 6.

Special Considerations

It is worth noting that the efficacy of Molnupiravir is dependent on the timing of treatment, with the best results seen when used within 5 days of symptom onset 4. Additionally, further studies are required to confirm the use of Molnupiravir in vaccinated COVID-19 patients and against emerging variants 3.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.