RU486 is a medication used to induce a miscarriage in a pregnancy less than 10 weeks along. Better known as the abortion pill or Mifeprex (mifepristone), RU486 is only available with a prescription.

Update

On June 24, 2022, the Supreme Court overturned Roe v. Wade—ending the constitutional right to abortion. Each state now has the power to regulate or prohibit the procedure. Following that ruling, some states have enforced bans or severe restrictions on abortion. President Joe Biden has since signed an Executive Order to help protect some abortion access in the country.

An FDA-approved method of medical abortion, Mifeprex is used in combination with Cytotec (misoprostol). First approved in 2000, Mifeprex blocks the hormone progesterone, which is needed for the pregnancy to progress. Cytotec, taken 24 to 48 hours later, is a synthetic prostaglandin that causes uterine contractions (cramps). 

Taken properly, the abortion pill is safe and 96.7% effective in terminating a pregnancy. This article discusses how to use Mifeprex (RU486). It also details the side effects, precautions, drug interactions, and cost of the abortion pill.

How Do You Use RU486?

Using the abortion pill involves a three-step process that involves taking two different medicines that work to end a pregnancy. It is important to note that the abortion pill is not the same thing as the morning-after pill.

If you choose to use the abortion pill, there are three steps in the process:

  • First, you will be given RU486 (mifepristone) to take by mouth. This may be done at a healthcare provider’s office, medical clinic, or at home.
  • Next, 24 to 48 hours after taking the mifepristone, you will need to take a second medicine by mouth, usually at home. It is called misoprostol. Make sure that your healthcare provider gives you instructions for how and when to take the misoprostol.
  • Last, after about two weeks, you will need to follow-up with your healthcare provider. This is very important because your practitioner will make sure that the abortion pills have worked. Your healthcare provider may recommend that you undergo a blood pregnancy test or an ultrasound to make sure you are no longer pregnant.

If the abortion pill didn’t work, your healthcare provider will discuss your options with you. You may need an additional dose of medication or a procedure to complete the abortion.

How It Works

RU486 blocks the progesterone receptors in your body. Progesterone is the hormone responsible for causing the uterine lining to build up and prepare for pregnancy. The mifepristone causes the lining of your uterus to shed—so your pregnancy can no longer continue because the egg will have nothing to stay attached to.

In January 2023, the FDA permanently removed an in-person dispensing requirement for the abortion pill, allowing certified pharmacies to offer the medication in stores or by mail with a prescription from a certified prescriber.

Then, the misoprostol will cause uterine contractions. This allows your uterus to be emptied.

Who Can Use It?

The FDA has approved RU486 for women up to 10 weeks pregnant or up to 70 days after the first day of their last menstrual period. It can be used safely in women of any age, including those under 17 years old.

RU486 Side Effects

You should expect to feel some side effects after using the abortion pill.

These can include:

  • CrampingNauseaVomiting and diarrheaHeavy bleeding (there may be large clots in the blood)Stomach painFatigueMild fever or chills on the day you take the misoprostol

If you have severe pain or feel faint, get medical attention. And if you have a fever after the day you take the misoprostol, call your healthcare provider.

Contraindications

Mifeprex and its generic mifepristone should not be taken if it has been more than 70 days since the first day of your last menstrual period. The medication is also contraindicated for people with:

  • Adrenal gland diseasesAn allergy to mifepristone, misoprostol, or similar drugsBleeding problemsEctopic pregnanciesAn intrauterine device (IUD) in place (it should be removed before taking Mifeprex)Porphyria

Interactions

Mifeprex can negatively interact with certain medications. Before taking RU486, tell your healthcare provider if you are taking any of the following medications:

  • Cyclosporine (Gengraf, Neoral, Sandimmune)Dihydroergotamine (D.H.E. 45, Migranal) Ergotamine (Ergomar, Ergostat) Fentanyl (Sublimaze) Lovastatin (Altocor, Mevacor) Pimozide (Orap) Quinidine (Quinora) Simvastatin (Zocor) Sirolimus (Rapamune) Tacrolimus (Prograf) Steroid medicine (such as dexamethasone, hydrocortisone, methylprednisolone, prednisone, Medrol)

Length of Time and Efficacy 

Within four or five hours after taking the mifepristone, more than half of women’s pregnancies will be terminated. For others, it may take a little longer, but the abortion should take place within a few days. You can expect to see clots of blood when this happens, and the cramping may continue intermittently for a few days.

RU486 helps to terminate a pregnancy without surgery and is 92% to 98% effective when used in combination with misoprostol. When mifepristone is used alone, it is about 64% to 85% effective.

Advantages

  • EffectiveLess intrusive to the body than surgical abortionConsidered by some people to be a more natural abortion option since it feels similar to a miscarriagePrivateCan be used early in a pregnancy

Disadvantages

  • Some people are morally opposed to this method since conception and implantation have already taken place.Mifepristone may not be an option for women with liver or kidney problems, anemia, and diabetesThis method may require several visits to the healthcare provider, and there is a possibility that it may not work.If the abortion pill has not ended your pregnancy, there is a chance of birth defects if you carry the baby to term.

Other Considerations 

You can become pregnant again right after using the abortion pill, so make sure that you are using backup contraception. Also, know that RU486 does not offer protection against sexually transmitted diseases.

It is normal to have some bleeding or spotting for up to four weeks after using the abortion pill. It is recommended that you do not insert anything into your vagina or have sex for at least seven days after using the abortion pill.

Keep in mind that you may have all types of feelings after a medical abortion. Because of the sudden change in your hormone levels, you may become more emotional. It may help to know that most women report that the main emotion they feel afterward is relief, and just about all women who have used the abortion pill would recommend it to a friend.

The bleeding after your abortion marks the start of a new menstrual cycle. This means that your normal period should return in four to eight weeks.

How Much Does RU486 Cost?

You can check with your private insurance to see if they cover medical abortion. That being said, the abortion pill may cost up to $800, but it usually costs less. The final cost depends on whether or not you need additional tests, healthcare provider visits, and/or exams.

The cost of RU486 can also vary depending on your state. RU486 is available at many Planned Parenthood clinics. Contact a clinic in your area to find out about its availability, pricing, and if you qualify for any discounts.

A Word From Verywell

RU486 has been used for terminating unplanned pregnancies for years and has been an effective medical abortion option for many. Understanding how RU486 works and when it can be used, in addition to having thorough conversations with your healthcare provider about it, can help you know if it is the right choice for you.

Frequently Asked Questions

  • How long does Mifeprex stay in your body?
  • Mifeprex stays in your body and is detectable by blood test for up to 11 days.
  • What if bleeding does not occur after taking the abortion pill?
  • Bleeding typically begins two to four hours after Cytotec (misoprostol), the second medication in the series. If bleeding has not started 24 hours after taking it or if bleeding is very light, call your healthcare provider for guidance. In some cases, a second dose of Cytotec may be needed.
  • Can you drive home after taking the abortion pill?
  • Yes, it is safe to drive after taking Mifeprex (mifepristone/RU486), the first medication in the abortion pill series. This means you can drive yourself to your appointment and home again.It is also safe to drive after taking Cytotec (misoprostol). However, the second medication commonly causes cramping and heavy bleeding. Many women prefer to stay home and rest.
  • What’s the difference between RU486 and Plan B?
  • Plan B is an emergency contraception drug that’s taken by mouth to prevent an unintended pregnancy after unprotected sex or contraceptive failure (like a broken condom or a displaced IUD). Plan B is not an abortion pill and it will not work if you are already pregnant. RU486 is a medical abortion option that is taken by mouth and used when a woman is already pregnant.
  • Can I buy an abortion pill from the pharmacy?
  • Yes, you can buy an abortion pill from a certified pharmacy in stores or by mail order, with a prescription written by a certified prescriber.
  • When can you get an abortion?
  • Currently, the FDA has approved mifepristone/RU486, used together with misoprostol, for abortions for up to 10 weeks into a pregnancy (70 days or less since the first day of the last menstrual period).
  • Does RU486 treat ectopic pregnancies?
  • No, Mifeprex (mifepristone/RU486) is not approved to treat an ectopic pregnancy. Studies show it is not effective in expelling an ectopic pregnancy.
  • Where does the term RU486 come from?
  • RU486 is the proprietary trade name for Mifeprex (mifepristone). The term RU486 was used in pre-clinical studies and news articles about the abortion pill before it received FDA approval. Today it is more commonly known by its brand name Mifeprex, its generic name mifepristone, or simply the abortion pill.

Mifeprex stays in your body and is detectable by blood test for up to 11 days.

Bleeding typically begins two to four hours after Cytotec (misoprostol), the second medication in the series. If bleeding has not started 24 hours after taking it or if bleeding is very light, call your healthcare provider for guidance. In some cases, a second dose of Cytotec may be needed.

Yes, it is safe to drive after taking Mifeprex (mifepristone/RU486), the first medication in the abortion pill series. This means you can drive yourself to your appointment and home again.

Plan B is an emergency contraception drug that’s taken by mouth to prevent an unintended pregnancy after unprotected sex or contraceptive failure (like a broken condom or a displaced IUD). Plan B is not an abortion pill and it will not work if you are already pregnant. RU486 is a medical abortion option that is taken by mouth and used when a woman is already pregnant.

Yes, you can buy an abortion pill from a certified pharmacy in stores or by mail order, with a prescription written by a certified prescriber.

Currently, the FDA has approved mifepristone/RU486, used together with misoprostol, for abortions for up to 10 weeks into a pregnancy (70 days or less since the first day of the last menstrual period).

No, Mifeprex (mifepristone/RU486) is not approved to treat an ectopic pregnancy. Studies show it is not effective in expelling an ectopic pregnancy.

RU486 is the proprietary trade name for Mifeprex (mifepristone). The term RU486 was used in pre-clinical studies and news articles about the abortion pill before it received FDA approval. Today it is more commonly known by its brand name Mifeprex, its generic name mifepristone, or simply the abortion pill.