An oral antiviral for COVID-19
Molnupiravir
An oral COVID-19 capsule for early treatment in higher-risk people, taken as a short course.
What is Molnupiravir?
Molnupiravir is an antiviral taken by mouth as a capsule, used for the early treatment of COVID-19 in people at higher risk of becoming seriously unwell. It is taken as a short course and works best when started soon after symptoms begin. It is not used in pregnancy, and contraception is advised during treatment and for a short time afterwards. It is one of several COVID-19 treatments, and your team will decide if it is right for you. The brand name is Lagevrio.
Education and reference only. This is a plain-language guide to Molnupiravir — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Molnupiravir is an antiviral medicine taken by mouth as a capsule to treat COVID-19, the illness caused by the coronavirus. It is used for people who are at higher risk of becoming seriously unwell, such as some people with weakened immunity or other risk factors. It is taken as a short course over a few days and should be started early, soon after a positive test and the start of symptoms. The brand name is Lagevrio.
How it works
Molnupiravir works by causing the coronavirus to make errors when it copies its genetic material. As the virus tries to multiply, these mounting mistakes stop it from producing working copies of itself, so the infection is brought under control more quickly. Because this effect depends on the virus actively multiplying, the medicine is most useful when it is started early in the illness rather than later on.
Company & origin
Originated / developed by: Merck Sharp & Dohme.
An oral antiviral used in the UK for early treatment of COVID-19 in people at higher risk of becoming seriously unwell.
Practical use
How to take Molnupiravir
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take the capsules by mouth as a short course, exactly as prescribed, with or without food.
- Swallow the capsules whole rather than opening or crushing them.
- Start it early, soon after symptoms and a positive test, as it works best when begun promptly.
- Use effective contraception during treatment and for the period afterwards your team advises, as it is not for use in pregnancy.
- Finish the full short course even if you feel better, unless your team tells you to stop.
Weighing it up
Advantages & disadvantages of Molnupiravir
Advantages
- An oral capsule that can be taken at home, with no need for a drip.
- Used for early treatment in higher-risk people to reduce the chance of becoming seriously unwell.
- Taken as a short, convenient course over a few days.
Disadvantages
- Not for use in pregnancy or breastfeeding, and contraception is advised.
- Works best only when started early in the illness.
- Not recommended for children and young people.
Practical use
Good to know
Molnupiravir is taken as a short course of capsules and should be started early, ideally within a few days of symptoms beginning, so it is offered promptly to those who qualify. It is generally well tolerated, with side effects such as nausea, diarrhoea or dizziness usually being mild. The most important caution is that it is not recommended in pregnancy, and it is also not advised while breastfeeding; effective contraception is advised for women who could become pregnant during treatment and for a short time afterwards, and men are advised to use contraception for a period after the course as a precaution. It is not recommended for children and young people. It is one of several COVID-19 treatments, and your team chooses based on your situation, the timing of your illness and your other medicines.
Who should not take it / use with caution
- It is not recommended in pregnancy or while breastfeeding.
- It is not recommended for children and young people.
- Anyone who has had a serious reaction to molnupiravir before should not take it.
Monitoring
- Confirming you qualify and that treatment is started within the recommended early window.
- Checking for pregnancy and contraception needs before and during treatment.
- Reviewing your symptoms and response over the short course.
Side effects
- Nausea, diarrhoea and dizziness, which are usually mild.
- Headache in some people.
- Rarely, rash or other allergic-type reactions.
Key interactions
- It has few known interactions with other medicines, but your team still reviews your full list.
- It is not combined with certain other COVID-19 antivirals unless specifically advised.
- Tell your team about all your medicines and any chance of pregnancy before starting.
Available as: Capsules taken by mouth.
Answers
Molnupiravir: frequently asked questions
What is molnupiravir used for?
It is an oral antiviral used for the early treatment of COVID-19 in people at higher risk of becoming seriously unwell.
Why must it be started early?
It works by disrupting the virus as it multiplies, so it is most helpful when started soon after symptoms begin.
Can I take it if I am pregnant?
No, it is not recommended in pregnancy or while breastfeeding, and contraception is advised during treatment and for a short time afterwards.
How is it taken?
It is taken by mouth as a short course of capsules over a few days; swallow them whole and finish the course as directed.
Is it suitable for children?
No, molnupiravir is not recommended for children and young people.
Authoritative sources
- BNF
- NICE CKS
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