How does Paxlovid work?
Paxlovid is a combination of 2 medicines called nirmatrelvir and ritonavir.
Nirmatrelvir stops COVID-19 from growing and spreading. It works by preventing the virus from multiplying and keeping virus levels low in your body. This helps your body's immune system control the infection and reduces the risk of severe symptoms.
Ritonavir does not work on the virus itself. It helps keep nirmatrelvir from being broken down in your body long enough for it to do its job.
How long does it take to work?
Paxlovid starts to work soon after you take it. It works best when taken as soon as possible after getting a positive COVID-19 test and within 5 days of your symptoms starting.
Everyone has a different experience of COVID-19, especially if you have risk factors for getting severely ill.
Most people who take Paxlovid will recover quickly after taking this medicine, with a reduced risk of severe illness.
Are there any long-term side effects?
It's not known if there are any long-term side effects from taking Paxlovid.
What will happen if I stop taking it?
Do not stop taking Paxlovid before the end of your 5 day course without talking to your doctor first.
If you stop taking Paxlovid before the end of the course, it may no longer protect you from becoming severely ill from COVID-19.
How does Paxlovid compare with other medicines to treat COVID-19?
There are other antiviral medicines that are also effective in preventing severe illness from COVID-19:
- molnupiravir (Lagevrio) tablets
- remdesivir (Veklury) - given as a drip into your arm (infusion)
If antiviral medicines are not suitable for you, sotrovimab may be offered instead. Sotrovimab is a biological medicine. It’s also known as a neutralising monoclonal antibody (nMAb).
COVID-19 treatments do not replace vaccinations. Vaccines are given to help your immune system fight a future COVID-19 infection.
How effective is Paxlovid?
If you have COVID-19, Paxlovid reduces your risk of severe symptoms and needing hospital treatment.
It's important to take Paxlovid within 5 days of your COVID-19 symptoms starting, to give it the best chance of working.
Will it affect my contraception?
If you have COVID-19, it's important that you do not have contact with other people. This is to avoid passing the infection on.
Paxlovid can stop combined oral contraceptive pills ("the pill") from working properly.
If you are taking Paxlovid it's important to use effective contraception (a condom, female condom, diaphragm or cap) for the full 5 days of treatment and until you've had one full menstrual cycle.
If you take contraception and Paxlovid makes you vomit or have severe diarrhoea for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Check the pill packet to find out what to do.
Find out more about what to do if you're on the pill and you're being sick or have diarrhoea.
Can I drive or ride a bike?
If you're being treated for COVID-19, stay at home to avoid passing the infection on to other people.
If you feel dizzy, do not drive a car, ride a bike, or use tools or machinery.
It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.
GOV.UK has more information on the law on drugs and driving.
Can I drink alcohol while taking Paxlovid?
It's not known if alcohol affects Paxlovid.
Is there any food or drink I need to avoid?
You can eat and drink normally while you're taking Paxlovid.