Mifepristone is an abortion pill. The abortion pill is a less complicated way to end a pregnancy up to 11 weeks after the first day of your last period. You can usually carry out part of the procedure at home, which can be more comfortable for some people.

But that can lead to anxiety about whether the pill has worked.

Although a follow-up appointment is the best way to get reassurance, there are a number of signs to look out for that point to abortion pill success.

Does Mifepristone work? 

Most people experience cramping and bleeding within a few hours of taking the second pill, misoprostol. This is a good indicator that the abortion pill has worked. Bleeding, or the passing of large blood clots shows that the fetal tissue is exiting the body.

Cramping helps the uterus return to its usual state. Your healthcare provider will also schedule a follow-up appointment a couple of weeks later to check that the abortion pill worked.

How long does Mifepristone usually take?

The abortion pill comes in two separate doses. The process usually takes 1 to 2 days to complete. You may experience symptoms for a few weeks after taking both pills.

You’ll first have an appointment with a nurse or doctor who will ask about your medical history and explain how the process works. If you haven’t had a recent ultrasound, they will perform one to see how far along the pregnancy is.

Uses of Mifepristone

Mifepristone (also known as RU 486) is used during the early part of a pregnancy to induce an abortion. It is used up to week 10 of pregnancy (up to 70 days after the first day of your last menstrual period). 

Mifepristone blocks a natural substance (progesterone) required for your pregnancy to proceed. Typically, it is used in conjunction with another drug called misoprostol. If you have a rare, irregular pregnancy outside the womb, Mifepristone must not be used (ectopic pregnancy).

In this instance, it will not cause an abortion. It may cause the rupture of an ectopic pregnancy, resulting in very significant bleeding.

How to use Mifepristone?

Before you start using Mifepristone:

  1. Read the Drug Guide supplied by your doctor. If required, hold the guide for rereading.
  2. Consult your physician or pharmacist if you have any questions.
  3. Read and sign the form given by your doctor with the Patient Agreement. If you do not understand how to use this drug or are unable to obey the instructions, tell your doctor.

Mifepristone can only be administered by your doctor. It is not available in drug stores. To complete your medication and critical tests, you need to visit the doctor’s office at least two times.

This care is only provided in a doctor’s office, clinic, or hospital under strict medical supervision. Be sure to have concise instructions from your doctor regarding whom to call and what to do in case of an emergency.

To ensure your pregnancy is less than ten weeks and is not outside the womb (ectopic), your doctor will want to do an ultrasound.

Take Mifepristone by mouth, usually as one single dose, as instructed by your doctor. Your doctor can direct you to wait 24 to 48 hours before taking another drug (misoprostol) by mouth as a single dose after you have taken Mifepristone.

If you take misoprostol earlier than 24 hours after taking Mifepristone or later than 48 hours after taking Mifepristone, the drug does not function as well. Carefully follow the directions of your doctor. Heavy vaginal bleeding does not mean the completion of abortion.

Do not take grapefruit juice when using this drug, except when instructed by a Doctor. It is imperative that you return for a follow-up visit after taking Mifepristone within 7 to 14 days, even if you do not have any problems.

Surgery may be required if abortion does not occur or is not complete if there are severe medical complications. There is a chance of congenital disabilities if the procedure fails, and the pregnancy continues, and you give birth to the child.

Side Effects


A medication, along with its desired effects, can cause some unwanted side effects. While not all of these side effects can occur, they can require medical attention if they occur.

There may be nausea, vomiting, diarrhea, fatigue, or dizziness. If these symptoms continue for more than the first 24 hours after the second medication (misoprostol) is administered, seek urgent medical attention as they may be signs of a serious medical condition.

During this procedure, bleeding and cramping are expected. The signs generally mean the medications are working. You may get cramps and bleeding often, though, and not be pregnant. Therefore, you must go back to the doctor for all of your follow-up appointments.

In the 24 hours after taking the second medication, nausea and cramping may worsen (misoprostol). In order to help with these symptoms, your doctor can direct you to take other medications. Tell your physician or pharmacist immediately if any of these symptoms persist or worsen.

It may last up to 30 days for bleeding and spotting and maybe much heavier than a regular time. This bleeding would need to be stopped by surgery in a few cases.

If you bleed enough to soak through 2 thick, full-size sanitary pads per hour for 2 hours in a row, or if you are worried about heavy bleeding, seek urgent medical attention. Check immediately with your doctor if any of the following other side effects occur:

Less common

  1. Excessively heavy vaginal bleeding
  2. Unusual tiredness or weakness

Incidence not known

  1. Pain or discomfort in the arms, jaw, back, or neck
  2. Confusion
  3. Cough or hoarseness
  4. Fast, weak pulse
  5. Painful or difficult urination
  6. Pale, cold, or clammy skin
  7. Shortness of breath
  8. lower back or side pain
  9. An unusual or large amount of vaginal bleeding
  10. A sudden increase in stomach or shoulder pain
  11. Sweating
  12. Chest pain or discomfort
  13. Fever or chills

There may be some side effects that typically don’t require medical attention. As your body responds to the medication, these side effects can go away during treatment.

Your health care provider will also be able to advise you about ways to minimize any of these side effects or reduce them. If any of the following side effects persist or are bothersome, check with your health care provider or if you have any concerns about them:

Less common

  1. Heartburn
  2. Increased clear or white vaginal discharge
  3. Indigestion
  4. Pain or tenderness around the eyes and cheekbones
  5. Pale skin
  6. Shaking chills
  7. Stomach discomfort, upset, or pain
  8. Stuffy or runny nose
  9. Trouble sleeping
  10. Troubled breathing
  11. Troubled breathing, exertional
  12. Unusual bleeding or bruising
  13. Fainting or lightheadedness when getting up from a lying or sitting position
  14. Fever
  15. Flu-like symptoms
  16. Headache
  17. Itching of the vagina or genital area
  18. Lack or loss of strength
  19. Pain during sexual intercourse
  20. Acid or sour stomach
  21. Anxiety
  22. Belching
  23. Cough
  24. The tightness of the chest

In certain patients, other side effects not reported can also occur. Check with your healthcare provider if you have any other results.

Know that this drug has been prescribed by your doctor, and he or she has decided that the value is greater than the risk of side effects. There are no significant side effects for many people who take this drug.

If you have any of these unlikely but very serious side effects, seek urgent medical attention: fever of 100.4 degrees F (38 degrees C) or higher, fainting, rapid pulse, stomach/abdominal pain, or tenderness.

In certain patients, other side effects not reported can also occur. Check with your healthcare provider if you have any other results.


Tell your doctor whether you are allergic to Mifepristone or misoprostol or some other progestin (such as norethindrone) or if you have any other allergies before taking Mifepristone.

There may be inactive ingredients in this substance that may cause allergic reactions or other problems. For more info, talk to your pharmacist.

If you have any medical problems or other concerns, this drug should not be used. Consult the doctor before taking this medication if you have any of the following conditions: undiagnosed abdominal development (adnexal mass), some adrenal gland issues (chronic adrenal insufficiency), bleeding problems (e.g., coagulopathy), some blood disorders (inherited porphyria), intrauterine birth control device (IUD) in place, pregnancy longer than ten weeks, documented or probable premature pregnancy outside of the womb (ectopic pregnancy).

Intrauterine birth control devices (IUD) should be removed before treatment with mifepristone starts. Inform your doctor or pharmacist of your medical history before using this drug, particularly: low blood count (anemia), smoking more than ten cigarettes a day.

This medication must be used only if you can rapidly access adequate emergency care facilities in the event of a serious medical condition. With this drug, you might get dizzy.

You’ll feel dizzier if you ingest alcohol or cannabis (marijuana). Until you can do it safely, do not drive, use instruments, or do anything that requires caution. Do not take alcoholic beverages. Speak to the doctor if you use marijuana (cannabis).

Usually, Mifepristone causes fetal death. Birth defects may occur in the unlikely event that you have an ongoing pregnancy after treatment.

After this termination procedure and before your usual cycle starts again, another pregnancy can happen. It is possible to start birth control as soon as this procedure is successfully completed. For more details, consult your doctor.

It moves into breast milk with this drug. Although the effects of Mifepristone on children are unclear, breast-feeding mothers should consult their physicians as to whether their breast milk should be discarded for a few days after this procedure.


Drug interactions can affect the working of your drugs or increase the risk of serious side effects. Not all potential drug interactions are included in this paper.

Keep a list and share it with your doctor and pharmacist of all the medications you use (including prescription/nonprescription medicines and herbal products). Without your doctor’s permission, do not start, stop, or adjust the dosage of any medication.

Long-term corticosteroid treatment (such as prednisone), medications that affect liver enzymes that extract Mifepristone from the body (such as azole antifungals such as itraconazole/ketoconazole, macrolide antibiotics like erythromycin, dexamethasone, rifamycins including rifabutin, St. John’s wort, some anti-seizure medicines, like carbamazepine/phenytoin/phenobarbital), are some products that can interfere with this medicine.

Other medications that can cause bleeding/bruising (including antiplatelet drugs such as clopidogrel, NSAIDs such as ibuprofen/naproxen, “blood thinners” such as warfarin/dabigatran).

When used with this drug, aspirin can boost the risk of bleeding. However, if your doctor has advised you to take aspirin at low doses for heart attack or stroke prevention (usually at doses of 81-325 milligrams a day), you should continue to take it unless otherwise prescribed by your doctor. For more info, ask your doctor or pharmacist.

Mifepristone may slow down the removal from the body of other drugs that can affect how they function. Cyclosporine, ergot alkaloids (such as dihydroergotamine, ergotamine), fentanyl, pimozide, quinidine, some statin medications (such as fluvastatin, lovastatin, simvastatin), sirolimus, tacrolimus, warfarin, and others, are all examples of affected drugs.


Call 911 if someone has overdosed and has extreme symptoms, such as passing out or difficulty breathing. Otherwise, immediately contact a poison control center.

US residents should dial 1-800-222-1222 from their nearest poison control center. Residents of Canada should call a regional center for poison control. Overdose signs can include the following: serious vaginal bleeding.


To monitor the development, laboratory, and/or medical tests (e.g., ultrasound) may be conducted. Maintain all expected medical appointments (at least two will be required).

Missed Dose

As instructed by your doctor, you must obey the dosing and appointment schedule. Contact your doctor right away if you miss an appointment.


This medication can only be taken from your doctor. Mifepristone is kept at room temperature, free from light and moisture, at 77 degrees F (25 degrees C). Brief 59-86 degree F storage

Who should not take Mifepristone?

The following conditions are contraindicated with this drug. Check with your physician if you have any of the following:


  • Significant reduction of the activity of the adrenal gland cortex
  • A sudden reduction in the activity of the adrenal glands 
  • Hereditary liver metabolism disorder
  • Hepatic porphyria
  • Erythropoietic protoporphyria
  • Variegate porphyria
  • Porphyria cutanea tarda
  • Heightened risk of bleeding due to a clotting disorder
  • High levels of white blood cells
  • A pregnancy that occurs outside of the womb
  • An increased risk of bleeding
  • Pneumonia with a fungus called Pneumocystis jirovecii
  • Cancer in the lining of the uterus
  • Low amount of potassium in the blood
  • Abortion complicated by an infection
  • Abnormal EKG with QT changes from birth
  • Overgrowth of the uterine lining
  • Pregnancy


  • Prostaglandins
  • Prostaglandins F2a
  • Prostaglandins E1
  • Prostaglandins E2