What is Mifepristone?

Mifepristone is a prescription medicine used as part of medication abortion care. It works by blocking progesterone, a hormone that helps maintain pregnancy. When mifepristone is used with misoprostol, the combination is used to end an early intrauterine pregnancy.

For many people researching medication abortion, understanding what each medicine does is an important part of making an informed decision. This guide explains what mifepristone is, how it works, how it is used with misoprostol, who may not be a candidate, what side effects and warning signs to know about, and why medical evaluation matters.

Important: Mifepristone is a prescription medicine. Whether it is appropriate for you depends on factors such as how far the pregnancy has progressed, whether the pregnancy is located inside the uterus, your medical history, and other medicines you may take. A licensed healthcare professional should determine whether it is appropriate for your situation.

What Is Mifepristone?

Mifepristone is a medication that blocks the action of progesterone, a hormone involved in maintaining pregnancy.

For medication abortion, mifepristone is used together with misoprostol. The FDA-approved regimen in the United States is indicated for ending an intrauterine pregnancy through 70 days of gestation, or 10 weeks measured from the first day of the last menstrual period.

Mifepristone is also known by brand names including Mifeprex. Generic mifepristone tablets are also approved in the United States. It is important to distinguish mifepristone products used for medication abortion from other medicines that contain mifepristone but are approved for different medical conditions.

What does mifepristone do?

Progesterone supports the uterine lining during pregnancy. Mifepristone blocks progesterone's action.

This prepares the uterus for the second medicine, misoprostol, which causes the uterus to contract and helps expel the pregnancy tissue.

In simple terms:

Mifepristone blocks progesterone → misoprostol causes uterine contractions → the pregnancy is expelled.

The two medicines have different roles. Mifepristone is not simply a pain medicine or a medicine that causes uterine contractions by itself.

How Does Mifepristone Work?

Mifepristone belongs to a class of medicines called progesterone receptor antagonists.

During pregnancy, progesterone helps maintain the uterine lining and supports the pregnancy. By blocking progesterone's action, mifepristone changes the uterine environment and makes the pregnancy more likely to be expelled when misoprostol is subsequently used.

The FDA describes the approved U.S. medication abortion regimen as 200 mg of mifepristone taken by mouth, followed 24 to 48 hours later by misoprostol. The FDA-approved regimen includes follow-up with a healthcare provider to confirm that the pregnancy has ended.

The exact instructions a patient receives should come from the prescribing healthcare professional and the medication's current prescribing information.

What Is the Difference Between Mifepristone and Misoprostol?

Mifepristone and misoprostol are different medicines that work in different ways.

Using the combination is an established approach to medication abortion. WHO guidance recognizes mifepristone plus misoprostol as a medical abortion regimen, and notes that the combination is more effective than misoprostol alone.

This distinction is useful when reading medication instructions because the medicines are not interchangeable.

What Is Mifepristone Used For?

Mifepristone has more than one medical use, depending on the specific product and dosage.

For medication abortion, mifepristone is used with misoprostol to end an early intrauterine pregnancy. In the United States, the FDA-approved indication covers an intrauterine pregnancy through 70 days of gestation.

Mifepristone is also used in a different product for the treatment of certain people with Cushing's syndrome. That use involves a different indication and should not be confused with mifepristone used for medication abortion.

For this reason, the name of the medicine alone does not tell you which treatment it is being used for. The product, dose, indication, and prescribing instructions all matter.

Who May Be Eligible for Mifepristone for Medication Abortion?

Eligibility is determined individually by a qualified healthcare professional.

Factors that may be considered include:

• How far the pregnancy has progressed
• Whether the pregnancy is located inside the uterus
• Relevant medical conditions
• Current medications
• Allergies or previous reactions to the medicines
• Certain bleeding disorders or use of blood-thinning medicines
• Whether appropriate follow-up and emergency care are available when needed

In the United States, the FDA-approved medication abortion indication for mifepristone applies to an intrauterine pregnancy through 70 days of gestation.

Gestational age is only one part of determining whether medication abortion is appropriate.

Why Does Pregnancy Location Matter?

Mifepristone and misoprostol are used to end an intrauterine pregnancy. They do not treat an ectopic pregnancy.

An ectopic pregnancy occurs when a pregnancy develops outside the uterus, most commonly in a fallopian tube. It can become a medical emergency if it ruptures.

This is one reason medical assessment is important before medication abortion. A healthcare professional may use your medical history, pregnancy dating information, symptoms, examination, or other evaluation methods to assess whether an ectopic pregnancy is a concern.

The FDA specifically notes that mifepristone is indicated for intrauterine pregnancy and that patients with an ectopic pregnancy are not appropriate candidates for the medication abortion regimen.

How Is Mifepristone Taken for Medication Abortion?

For the FDA-approved U.S. regimen, mifepristone is taken orally on the first day, followed 24 to 48 hours later by misoprostol. The FDA describes the approved regimen as 200 mg of mifepristone followed by 800 micrograms of buccal misoprostol. Follow-up is used to confirm that the pregnancy has ended.

However, medication instructions can vary according to the clinical situation and applicable medical guidance.

Do not change the dose, timing, route, or number of tablets based on information from a website alone. Follow the instructions provided by your prescribing healthcare professional and the medication guide supplied with your medicine.

What Can You Expect After Taking Mifepristone?

Mifepristone itself may cause few noticeable symptoms for some people. The more noticeable effects of medication abortion commonly occur after misoprostol, because misoprostol causes the uterus to contract.

People may experience:

• Vaginal bleeding
• Cramping
• Passage of blood clots or pregnancy tissue
• Nausea
• Vomiting
• Diarrhea
• Headache
• Dizziness
• Chills or a temporary feeling of fever

The amount of bleeding and the intensity of cramping can vary from person to person.

Your healthcare professional should explain what to expect based on the treatment regimen prescribed for you and when you should seek medical attention.

What Are the Common Side Effects of Mifepristone?

Side effects associated with medication abortion can include gastrointestinal symptoms, headache, dizziness, cramping, and bleeding.

It is important to distinguish expected effects from symptoms that may indicate a complication.

The FDA medication information warns about serious complications, including very heavy or prolonged bleeding and serious infection, which can occur rarely after medication abortion.

Having some bleeding and cramping does not necessarily mean that something is wrong. However, severe, unusual, or persistent symptoms should not be ignored.

When Should You Seek Medical Care?

Seek urgent medical attention if you experience symptoms that may indicate a serious complication.

Examples include:

• Very heavy vaginal bleeding
• Severe or persistent abdominal pain
• Fainting or loss of consciousness
• Severe weakness or feeling extremely unwell
• Persistent fever or other signs of infection
• Symptoms that concern you or become significantly worse

The FDA advises patients to know whom to contact and what to do if they experience sustained fever, severe abdominal pain, prolonged heavy bleeding, or fainting.

One commonly used FDA warning threshold for heavy bleeding is soaking through two full-size sanitary pads per hour for two consecutive hours. MedlinePlus advises contacting a healthcare professional or seeking emergency medical care if this occurs.

If you believe you may have an emergency, seek emergency medical care rather than waiting for an online response.

Can Mifepristone Cause an Ectopic Pregnancy?

No. Mifepristone does not cause an ectopic pregnancy.

However, mifepristone and misoprostol do not treat an existing ectopic pregnancy. This is an important distinction.

If someone has an ectopic pregnancy, taking medication abortion does not replace appropriate treatment for that condition. This is why pregnancy location and symptoms are important parts of clinical assessment.

Who Should Not Take Mifepristone for Medication Abortion?

Mifepristone is not appropriate for everyone.

The prescribing information identifies medical situations in which the medication abortion regimen should not be used. These include, among others, an ectopic pregnancy or suspected ectopic pregnancy and certain conditions involving bleeding or long-term corticosteroid use.

A healthcare professional should review your medical history before prescribing the medication.

Do not assume that you are eligible based only on your pregnancy duration.

Can Mifepristone Be Used With Other Medicines?

Potential interactions depend on the medicines you take and your individual medical history.

Tell your healthcare professional about:

• Prescription medicines
• Over-the-counter medicines
• Vitamins and supplements
• Blood thinners
• Corticosteroids
• Any known medication allergies

Do not stop a prescribed medicine on your own simply because you are considering medication abortion. Ask the prescribing healthcare professional how your existing medicines affect your treatment.

Is Mifepristone the Same as the “Abortion Pill”?

The phrase “abortion pill” is commonly used to describe medication abortion, but medication abortion typically involves two medicines: mifepristone and misoprostol.

Mifepristone is one component of the regimen. Misoprostol is the second medicine.

Using the more precise terms can make medical information easier to understand and helps avoid confusion about what each medication actually does.

Is Mifepristone FDA Approved?

Yes. The FDA first approved Mifeprex (mifepristone) in 2000. The FDA later approved a generic version, Mifepristone Tablets, 200 mg, in 2019. For medication abortion, the FDA-approved indication is use with misoprostol to end an intrauterine pregnancy through 70 days of gestation.

Mifepristone is subject to a federal Mifepristone Risk Evaluation and Mitigation Strategy (REMS) in the United States. The current REMS establishes requirements for prescribing and dispensing the medication.

FDA requirements and regulations can change, so patients and providers should rely on current FDA information and current prescribing materials rather than older articles.

Can Mifepristone Be Dispensed by Mail?

In the United States, the FDA's current information states that mifepristone may be dispensed in person or by mail under the Mifepristone REMS, subject to the program's requirements. Certified pharmacies may dispense mifepristone on a prescription issued by a certified prescriber.

Whether medication abortion is available by telehealth or mail depends on the applicable federal requirements, state law, provider practices, and the patient's clinical circumstances.

This is why availability should be confirmed with a qualified healthcare professional rather than assumed from information on a general website.

Does Mifepristone End a Pregnancy Immediately?

No.

Mifepristone begins the medication process by blocking progesterone. Misoprostol is then used to cause uterine contractions and expel the pregnancy.

Bleeding and cramping generally occur as the abortion process takes place, but the experience varies.

Follow-up is important because symptoms alone do not always establish whether the abortion is complete. The FDA-approved regimen includes follow-up with a healthcare provider to confirm completion.

What Happens if the Pregnancy Continues?

If a pregnancy continues after mifepristone and misoprostol, medical follow-up is important.

Do not take additional doses on your own without speaking with a healthcare professional. The appropriate next step depends on the circumstances, including pregnancy duration, symptoms, and the medications already taken.

If pregnancy continues after exposure to medication abortion medicines, discuss the situation promptly with a healthcare professional so that appropriate follow-up can be arranged.

Does Mifepristone Affect Future Fertility?

Current medical guidance does not identify medication abortion as a cause of infertility.

Fertility can return relatively quickly after an abortion, which means pregnancy can occur again soon afterward.

If you do not want another pregnancy, discuss contraception with a healthcare professional. If you are planning a future pregnancy, your healthcare professional can also discuss when you can begin trying to conceive.

Mifepristone vs. Surgical Abortion

Medication abortion and procedural abortion are different approaches to ending a pregnancy.

Medication abortion uses medicines to end and expel a pregnancy.

Procedural abortion uses a medical procedure to remove pregnancy tissue from the uterus.

Which option is appropriate can depend on pregnancy duration, medical history, personal preference, local availability, and clinical circumstances.

A healthcare professional can explain the available options and help determine which approaches are medically appropriate.

Why Medical Review Matters

Mifepristone is a prescription medication, so determining whether it is appropriate involves more than confirming a positive pregnancy test.

A clinical review may consider:

1. Pregnancy duration — to determine whether the medication is appropriate for the stage of pregnancy.
2. Pregnancy location — because medication abortion does not treat ectopic pregnancy.
3. Medical history — including conditions that may affect treatment.
4. Current medicines — particularly medicines that may affect bleeding or interact with treatment.
5. Symptoms and risk factors — to identify situations requiring further evaluation.
6. Follow-up and emergency care — to make sure appropriate care is available if a complication occurs.

The FDA states that certified prescribers must be able to assess pregnancy duration, diagnose ectopic pregnancy, and ensure access to appropriate emergency and surgical care or make arrangements for it.

This is why online information should support, rather than replace, individualized medical assessment.

Frequently Asked Questions About Mifepristone

Is mifepristone the same as misoprostol?

No. They are different medicines with different roles. Mifepristone blocks progesterone, while misoprostol causes uterine contractions and helps expel the pregnancy.

How many weeks can mifepristone be used for medication abortion?

In the United States, the FDA-approved mifepristone regimen with misoprostol is indicated for an intrauterine pregnancy through 70 days, or 10 weeks, of gestation. Other clinical guidelines and legal requirements may differ by setting.

Do I need an ultrasound before taking mifepristone?

Not everyone necessarily needs an ultrasound. The appropriate method for confirming gestational age and assessing the possibility of ectopic pregnancy depends on the clinical situation. The FDA states that an in-person visit is not mandated by the Mifepristone REMS itself.

Does mifepristone work by itself?

Mifepristone is generally used with misoprostol for the FDA-approved medication abortion regimen in the United States. Follow the regimen provided by your healthcare professional.

Does mifepristone cause bleeding?

Bleeding is part of the medication abortion process and is generally associated with the combination of mifepristone and misoprostol. Heavy or prolonged bleeding can be a sign of a complication and requires medical attention.

Can mifepristone treat an ectopic pregnancy?

No. Mifepristone and misoprostol do not treat ectopic pregnancy. Suspected ectopic pregnancy requires appropriate medical evaluation and treatment.

Can I take mifepristone without medical guidance?

Mifepristone is a prescription medication, and eligibility should be assessed by a qualified healthcare professional. Medical guidance is particularly important for determining pregnancy duration, considering contraindications, identifying ectopic pregnancy risk, and explaining follow-up and warning signs.

The Bottom Line

Mifepristone is a prescription medicine that blocks progesterone and is used with misoprostol for medication abortion. In the United States, the FDA-approved regimen is indicated for ending an intrauterine pregnancy through 70 days of gestation.

Understanding how mifepristone works can help you make sense of medication abortion, but eligibility cannot be determined from a general article alone. A qualified healthcare professional should review your circumstances, explain the treatment, discuss potential risks and side effects, and provide instructions for follow-up and urgent care when needed.

For reliable medication information, use current FDA-approved prescribing information and medication guides together with guidance from your healthcare professional.

Medical Information Disclaimer

This article is for general educational purposes and is not a substitute for individualized medical advice, diagnosis, or treatment. Medication abortion should be discussed with a qualified healthcare professional who can assess your medical history and individual circumstances. If you experience symptoms that may indicate an emergency, seek urgent medical care.