An antiprogestogen
Mifepristone
A medicine that blocks progesterone, used under medical supervision in the management of miscarriage and in ending a pregnancy.
What is Mifepristone?
Mifepristone blocks progesterone, a hormone the body needs to maintain a pregnancy. It is used under medical care, usually followed by a second medicine called misoprostol, in the medical management of miscarriage and in ending a pregnancy, and to soften and prepare the womb and cervix beforehand. It is always given as part of a supervised plan, with clear advice on what to expect, such as bleeding and cramping, and on when to seek help. This is a factual description; decisions about its use are personal and made with a clinician.
Education and reference only. This is a plain-language guide to Mifepristone — 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
Mifepristone is an antiprogestogen, meaning it blocks the action of progesterone, the hormone that prepares and maintains the lining of the womb in pregnancy. In the UK it is used within supervised care to manage a miscarriage that is not completing on its own and to end a pregnancy, and to prepare the womb and cervix so a second medicine can work. It is taken by mouth as a tablet and is provided by specialist services, not bought over the counter.
How it works
Because pregnancy depends on progesterone, blocking that hormone with mifepristone causes the lining of the womb to begin to break down and makes the cervix softer and more responsive. A second medicine, misoprostol, is then usually given a short time later to cause the womb to contract and empty. Using the two together is more effective than either alone, which is why mifepristone is described as preparing the womb for the step that follows.
Company & origin
Originated / developed by: Generic (specialist supply).
A medicine that blocks the hormone progesterone, used in the UK under medical supervision in early pregnancy care, including the management of miscarriage and ending a pregnancy.
Practical use
How to take Mifepristone
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is taken by mouth as part of a supervised plan; follow exactly the instructions your service gives you.
- A second medicine, misoprostol, is usually taken a set time later — keep to the timing you are given, as it matters for how well treatment works.
- Expect some bleeding and cramping, mainly after the second medicine; you will be told what is normal and what is not.
- Attend any follow-up arranged for you, as this confirms the process is complete and you are well.
- Keep the emergency contact details you are given, and seek urgent help if you have very heavy bleeding, severe pain or feel very unwell.
Weighing it up
Advantages & disadvantages of Mifepristone
Advantages
- Used with misoprostol, it provides an effective, well-established medical option within supervised care.
- Allows the womb and cervix to be prepared so the process works more reliably.
- Avoids surgery for many people, with care and follow-up arranged through a service.
Disadvantages
- Causes bleeding and cramping, which can be heavy at times, and may take time to settle.
- Requires a planned two-stage process and follow-up rather than a single dose.
- Is only available through specialist services and not for self-treatment.
Practical use
Good to know
Mifepristone is only used within supervised medical care, with information given beforehand about the process and aftercare. After taking it, some people have bleeding or spotting before the second medicine, though many have little until then. Cramping, bleeding and the passing of pregnancy tissue usually follow the misoprostol stage rather than mifepristone itself. It is important to follow the timing you are given for the second medicine and to keep any follow-up appointment, which confirms the process is complete. You should be told clear warning signs — such as very heavy bleeding, severe pain, a high temperature or feeling very unwell — that mean you should seek urgent help. Emotional support is part of good care, and services can signpost this. This page describes the medicine factually and without judgement; the decision to use it is a personal one made with a clinician.
Who should not take it / use with caution
- People with a confirmed or suspected ectopic (tubal) pregnancy, which needs different, urgent treatment.
- People with certain conditions, such as some adrenal problems, severe uncontrolled asthma or particular bleeding disorders, in whom a clinician will advise against it.
- Anyone for whom a clinician judges it unsuitable after reviewing their health and medicines.
Monitoring
- Follow-up to confirm the process is complete and that bleeding is settling.
- Advice on warning signs of heavy bleeding or infection and when to seek urgent help.
- Offer of contraception advice and emotional support as part of aftercare.
Side effects
- Bleeding and cramping are expected; nausea, tiredness, headache or dizziness can also occur.
- Some people have vomiting or diarrhoea, more often around the misoprostol stage.
- Rarely, very heavy bleeding or signs of infection that need urgent medical attention.
Key interactions
- Long-term steroid medicines may be affected, as mifepristone can reduce their effect, so a clinician will review this.
- Some medicines that change how the liver processes drugs can affect mifepristone, so tell your service everything you take.
- Anti-inflammatory painkillers are not usually a problem, but follow the pain-relief advice your service gives.
Available as: Tablets taken by mouth, provided through specialist services.
Answers
Mifepristone: frequently asked questions
What does mifepristone do?
It blocks progesterone, the hormone that maintains a pregnancy, and prepares the womb and cervix so that a second medicine, misoprostol, can work. It is used within supervised medical care.
Is it used on its own?
Usually it is the first of two medicines; misoprostol is taken a set time later. Using them together is more effective than either alone.
Will I have bleeding after taking it?
Some people have bleeding or spotting after mifepristone, but most cramping, bleeding and passing of tissue happens after the misoprostol stage. Your service will explain what to expect.
When should I seek urgent help?
Seek urgent help if you have very heavy bleeding, severe pain, a high temperature or feel very unwell. Keep the emergency contact details your service gives you.
Can I get it over the counter?
No. It is provided only through specialist medical services, with information, support and follow-up as part of the care.
Authoritative sources
- BNF
- NICE CKS
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