Mifepristone (a.k.a. RU486, abortion pill)

Mifepristone is an anti-progesterone, sometimes referred to as RU486. The drug was developed by Roussel-Uclaf, the French pharmaceutical company, hence the letters RU in RU486.

The drug was synthesised in April 1980 and was first licensed for use in France in September 1988.

This page presents a summary of information on mifepristone SPUC has collected, contained in this pdf. References are also included in the PDF.

Jump to: The spread of Mifepristone, What is it used for?, How does Mifepristone work?, Side effects, Use in the UK, England and Wales, Scotland, Quotes and Statements about Mifepristone

The spread of Mifepristone

Mifepristone was licensed in Britain as an abortion drug by the Medicines Control Agency in July 1991, Sweden 1992, then Austria, Belgium, Denmark, Finland, Germany, Greece, Luxembourg, the Netherlands, Spain, and Switzerland in 1999. In 2000, it was approved in Norway, Russia and Ukraine. Serbia and Montenegro approved it in 2001, Belarus and Latvia in 2002, Estonia in 2003, Moldova in 2004, Albania in 2005, Portugal in 2007, and Romania in 2008. In Italy the drug was approved on the July 30, 2009. It was approved in Hungary in 2005, but as of 2005 had not been released on the market. Mifepristone is not approved in Ireland or Poland. Globally, Mifepristone is approved for use in around 38 countries. 

The level of use of Mifepristone/prostaglandin varies between England and Wales, and Scotland. More information can be found in this pdf.

What is it used for?

RU486/Mifepristone was developed specifically to kill unborn life in the womb. The description of the drug's product characteristics states, under "Therapeutic indications":

  1. Therapeutic termination of pregnancy up to 63 days' gestation.
  2. Softening and dilatation of the cervix uteriprior to mechanical cervical dilation for pregnancy termination.
  3. For use in combination with a prostaglandin for termination of pregnancy between 13 and 24 weeks.
  4. Labour induction in foetal death in utero.

How does Mifepristone work?

Mifepristone works by blocking the effects of progesterone, the natural hormone which is required to maintain the lining of the uterus during pregnancy. Mifepristone starves the womb of progesterone, the lining of the womb breaks down, and it is lost along with the developing embryo or foetus.

The success rate of Mifepristone on its own is not high. Some studies have it as low as 54% (3) and Mifepristone is therefore often used with a prostaglandin, typically misoprostol (a synthetic hormone-like chemical given by vagina), which induces powerful contractions of the uterus and causes the dead embryo or foetus to be expelled from the womb.

For pregnancies of 13 to 24 weeks' gestation, Mifepristone (600mg) is taken by mouth. This is followed by a prostaglandin by vagina (1mg every three hours up to 5mg). If abortion does not occur 24 hours after the start of treatment, a repeat course of prostaglandin will be given.

In both cases, if the treatment fails, the baby will be aborted by a surgical method, either vacuum aspiration or dilation and curettage.

In 2017-18, the Welsh, Scottish and Westminster governments individually took steps towards reinterpreting the wording of the Abortion Act to permit the consumption of misoprostol at home, away from medical supervision.

Side effects

Use of Mifepristone/prostaglandin may cause any of the following: haemorrhage requiring blood transfusion, severe pain requiring strong pain killers, incomplete abortion, rupture of the uterus, vaginal bleeding, abdominal cramping, nausea, vomiting, diarrhoea, headache, muscle weakness, dizziness, flushing, chills, backache, difficulty in breathing, chest pain, palpitations, rise in temperature and fall in blood pressure. The number and diverse nature of the side effects of Mifepristone/prostaglandin point to the fact that these are powerful chemicals.

Because of the way that Mifepristone is administered, the woman is involved in the whole process, she takes the tablets herself and is fully aware of the effects that the drugs are having on her body as they happen. It is possible for the embryo or foetus to come away while she is at home, possibly alone.

Quotes and statements

"As Abortifacient procedures go RU486 is not at all easy to use. In fact it is more complex to use than the technique of vacuum extraction...a woman who wants to end her pregnancy has to "live" with her abortion for at least a week using this technique. It's an appalling psychological ordeal". (Edouard Sakiz, Chairman Roussel-Uclaf August 1990)

At a news conference on 17 May 2002, Dr Richard Hausknecht, medical director of Danco, the company which manufactures RU486 for the American market, admitted, "it [RU486] is not safer than a surgical abortion".

"There is much about RU486/PG that is fraught with risk and problems. As we have queried, what is the meaning of 'private' and 'de-medicalised' abortion that requires three or four doctor's visits to a specialised centre, includes the taking of two or perhaps five hazardous drug combinations, is accompanied by vaginal ultrasound, and too often has complications ranging from moderate bleeding to severe pain, and for some women blood transfusions? If this is a private and de-medicalised abortion experience, then the word 'private' has lost its definitional moorings." (RU486 Misconceptions Myths and Morals: Janice J Raymond, Renata Klein, Lynette J. Dumble. Pub. Institute on women and Technology 1991)

For more quotes and references about Mifepristone/RU486, please download the pdf on Mifepristone here.