What Are Abortion Pills Called? Mifepristone & More

The medications used to end a pregnancy are most commonly called mifepristone and misoprostol, taken as a two-drug combination often referred to simply as “abortion pills” or “medication abortion.” Mifepristone is sold under brand names like Mifeprex in the United States and Mifegyne in Europe, while misoprostol is widely known by its original brand name Cytotec. The pharmacology behind these two drugs is distinct, their effectiveness differs depending on whether they are used together or separately, and the ways people obtain them have shifted dramatically in recent years.

Mifepristone and How It Works

Mifepristone is a synthetic steroid that blocks the hormone progesterone, which the body needs to maintain a pregnancy. Without progesterone’s support, the uterine lining begins to break down and the pregnancy cannot continue. The drug was first developed in France in the early 1980s and has been used in clinical practice for more than 25 years; it is now registered in dozens of countries.¹ In the United States, it is FDA-approved under the brand name Mifeprex. You may also see it called RU-486, a label that dates back to its original laboratory designation in France. That name stuck in public debate but is rarely used in medical settings today.

Mifepristone does more than end pregnancies. At very low daily doses it can block ovulation, making it effective as an emergency contraceptive in single-dose form.¹ It has also been studied for managing certain tumors, Cushing syndrome, and uterine fibroids, though its primary regulatory approval in most countries is for pregnancy termination.

Misoprostol and Its Many Roles

Misoprostol is a synthetic version of a naturally occurring compound called prostaglandin E1. It was originally developed and marketed under the brand name Cytotec to protect the stomach lining in people taking anti-inflammatory painkillers. Its effects on the uterus, specifically softening and dilating the cervix while triggering contractions, were discovered afterward and turned it into one of the most widely used drugs in reproductive medicine.²

Because misoprostol is cheap, heat-stable, and does not require refrigeration, it is available in many countries where mifepristone is not. It appears on the World Health Organization’s List of Essential Medicines. Outside of abortion, obstetricians use it to induce labor, manage postpartum hemorrhage, and prepare the cervix before surgical procedures. Its versatility means it is stocked in hospitals for reasons that have nothing to do with pregnancy termination, which has made efforts to restrict it particularly complicated.

The Standard Two-Drug Regimen

The most common protocol for medication abortion pairs mifepristone with misoprostol. You take one tablet of mifepristone (200 mg) by mouth, then 24 to 48 hours later take misoprostol, usually 800 micrograms placed between the cheek and gum (buccally), under the tongue (sublingually), or vaginally. Mifepristone does the initial work of blocking progesterone and loosening the pregnancy from the uterine wall; misoprostol then causes contractions that expel it.

This combination is highly effective. A study of over 13,000 women who completed follow-up found an overall success rate of about 98%, with the highest effectiveness at earlier gestational ages and a modest decline as pregnancy progressed toward nine weeks.³ Another large analysis reported a similar figure of about 98% complete abortion through 59 days of gestation.⁴ Serious complications requiring hospital care were rare in both studies, with rates of hospitalization for infection and transfusion each well under one percent.³

Using Misoprostol Alone

Where mifepristone is unavailable, banned, or too expensive, misoprostol can be used by itself. This matters in large parts of the world where regulatory or supply-chain barriers block access to mifepristone. When used alone, misoprostol is still safe, but the numbers tell a more nuanced story about effectiveness, and the details hinge on dose, route of administration, and how many doses a person takes.

A 2023 systematic review and meta-analysis found that when patients were allowed at least three doses of 800 micrograms given vaginally, sublingually, or buccally, the failure risk was about 11%. Serious adverse events remained low: at most 0.2% of patients were hospitalized or needed a transfusion.⁵ A different analysis that looked at misoprostol-only regimens more broadly, including lower doses and oral-only protocols, found much more variation. Among over 12,000 patients, about 22% ultimately needed a surgical procedure, but results ranged dramatically depending on how the misoprostol was given. Higher initial doses (800 micrograms or more) given vaginally cut the risk of needing surgery to roughly a quarter of what lower oral doses produced.⁶

A more recent prospective study found much higher success rates for misoprostol alone: about 98% complete abortion without any procedural intervention among 637 participants, with a median time to pregnancy expulsion of 12 hours.⁷ The gap between this result and the older systematic reviews likely reflects improvements in dosing protocols and patient selection. The bottom line is that misoprostol alone works, but the combination with mifepristone remains more reliably effective and is the preferred approach when both drugs are accessible.

Methotrexate as an Older Alternative

Before mifepristone became widely available, some clinicians used methotrexate, a drug better known for treating cancer and autoimmune conditions, paired with misoprostol to end early pregnancies. Methotrexate works by blocking cell division, which halts the rapidly growing embryonic tissue. It is still used to treat ectopic pregnancies, where the embryo implants outside the uterus and mifepristone is not effective.⁸ In cases of cervical ectopic pregnancy, a single dose of methotrexate combined with vaginal misoprostol has been described as a useful alternative to surgery.⁹

Methotrexate has largely fallen out of use for routine medication abortion because it is slower-acting than mifepristone, has a harsher side-effect profile, and carries risks of serious birth defects if the pregnancy continues after a failed attempt. When people talk about “abortion pills” today, they almost never mean methotrexate. But the drug’s history is worth knowing because it occasionally surfaces in clinical discussions, especially for ectopic pregnancies where the standard mifepristone-misoprostol protocol does not apply.

What the Process Feels Like

Side effects from medication abortion are common and expected; the process of ending a pregnancy involves heavy bleeding and cramping by design. After taking misoprostol, most people experience lower abdominal pain that peaks within the first few hours. Bleeding is typically heavier than a normal period and may include clots. The median duration of significant bleeding in one study was about four days.⁷

Beyond the expected cramping and bleeding, the most frequently reported medication side effects are nausea, vomiting, diarrhea, and feeling feverish or having chills.¹⁰ The route of misoprostol administration influences which side effects are more pronounced. Oral misoprostol tends to cause more nausea, vomiting, and diarrhea in the first few hours compared to vaginal administration, while vaginally administered misoprostol can produce a slightly higher and longer-lasting fever.¹¹ Over-the-counter pain relievers like ibuprofen are the standard recommendation for managing cramping. Serious complications, including heavy bleeding requiring a transfusion or infection requiring hospitalization, occur in well under one percent of cases.¹⁰

Roughly 2% to 10% of patients across large case series ultimately need a surgical procedure for reasons like incomplete expulsion or ongoing pregnancy, though the lower end of that range is more representative of current protocols using the full mifepristone-plus-misoprostol combination.¹⁰ One important thing to keep in mind: ectopic pregnancy cannot be treated with medication abortion, and clinicians screen for it before prescribing. If someone takes abortion pills while unknowingly having an ectopic pregnancy, the medications will not resolve it, and the condition can become dangerous.

How People Access Abortion Pills Today

The way people obtain mifepristone and misoprostol has changed substantially in recent years, driven by both regulatory shifts and the expansion of telehealth during the COVID-19 pandemic. In the United States, mifepristone has long been subject to a special FDA restriction called a Risk Evaluation and Mitigation Strategy (REMS), which for years required patients to pick it up in person at a hospital, clinic, or medical office. This made mifepristone unique among FDA-approved drugs: it was the only medication patients had to collect in a clinical setting even though they did not have to take it under supervision there.¹²

That in-person dispensing requirement was suspended during the pandemic and eventually removed permanently by the FDA. Today, telehealth services can prescribe medication abortion after a remote consultation, and the pills can be mailed directly to a patient. The operational model typically involves five steps: patient engagement, a care consultation (often by video or phone), payment, medication dispensing by mail, and follow-up communication.¹³ In a study examining mail-order pharmacy dispensing after in-person screening, about 86% of participants received their medications within three days, and over 94% rated the delivery time as reasonable. Nearly all participants reported that their confidentiality was maintained during shipping.¹⁴

The shift to mail-order began even before the FDA formally lifted its in-person requirement. An early implementation study started enrolling patients at 11 clinics across seven states in January 2020, with clinics mailing medications from their own stock or through internal pharmacies.¹⁵ The result is that medication abortion has become increasingly decoupled from a physical clinic visit, though state laws vary widely on whether telehealth prescribing is permitted.

Self-Managed Abortion

Self-managed abortion refers to ending a pregnancy without direct clinical supervision, typically using misoprostol with or without mifepristone obtained outside traditional healthcare channels. This is not a fringe practice. The World Health Organization considers self-managed medication abortion safe and effective up to 12 weeks of gestation when the person has access to accurate information and a referral pathway to a health system if needed.¹⁶ Self-managed abortion is used across a wide range of settings globally, from countries with strict legal restrictions to those with fully legal access where someone might prefer to manage the process at home.¹⁷

The safety data around self-managed abortion largely mirrors the clinical trial data for misoprostol-based regimens. The primary risk comes not from the pharmacology of the drugs themselves but from using incorrect doses, counterfeit pills, or taking them too late in pregnancy without medical support. Organizations that provide information and support for self-managed abortion, such as hotlines staffed by medical professionals, exist in many countries and aim to fill the gap between full clinical care and no guidance at all.

Counterfeit Pills and Quality Concerns

When medications are legally restricted, informal markets fill the gap, and quality becomes a genuine concern. Illegal online pharmacies pose a persistent risk of supplying substandard or falsified drugs, and this risk is heightened around medications that are difficult to obtain through conventional channels.¹⁸ In countries where abortion pills are banned or heavily restricted, stories circulate about vendors passing off inert tablets like paracetamol as mifepristone or misoprostol.¹⁹

Anthropological research from Poland, where abortion was severely restricted until recently, found that “fake-talk,” the widespread discussion and fear of counterfeit pills, functioned as a social phenomenon in its own right. People worried about whether their medications were genuine, and that anxiety sometimes influenced decisions about whether to attempt medication abortion at all.¹⁹ Whether the pills in any given case were actually counterfeit or simply failed for pharmacological reasons is often impossible to determine after the fact. The practical takeaway is that source matters: medications obtained through regulated pharmacies or vetted telehealth services have undergone quality controls that unregulated online sellers have not.

Why Genetics Might Affect How Well Mifepristone Works

Most discussion of medication abortion focuses on the drugs and their protocols, but individual biology plays a role too. Mifepristone is metabolized in the liver by enzymes that vary from person to person based on genetic differences. A study examining two sets of gene variants found that people carrying a particular variant of the CYP3A4 enzyme had lower blood concentrations of mifepristone, though this did not significantly affect clinical outcomes.²⁰ A separate gene variant in the MDR1 gene, which codes for a protein that pumps drugs out of cells, did appear linked to whether mifepristone worked: patients with the common version of this gene had higher success rates than those with the mutant type.²⁰

This is early-stage research and not something clinicians currently screen for. But it suggests that the small percentage of people for whom medication abortion does not work may not simply have “bad luck.” Their bodies may process the drug differently in ways that are eventually predictable. The field of pharmacogenomics, which studies how genetic variation affects drug response, could in theory allow clinicians to adjust doses or select different protocols in advance, though that remains a future possibility rather than a current practice for medication abortion.

Abortion Medications in Veterinary Medicine

Mifepristone and misoprostol are not exclusively human drugs. Veterinarians use related compounds to manage unwanted pregnancies in animals, though the specifics differ. In dogs and cats, a drug called aglepristone fills a similar role to mifepristone by blocking progesterone receptors. Misoprostol is sometimes used alongside aglepristone, but the combination matters: misoprostol alone at safe doses did not reliably induce abortion in cats, while adding aglepristone made the regimen more effective than either drug alone.²¹

In dogs, studies have similarly compared various combinations of misoprostol and aglepristone for pregnancy termination during mid-gestation. When aglepristone was combined with intravaginal misoprostol, abortion was completed within six days in all animals, outperforming aglepristone alone.²² Veterinary researchers continue to evaluate different application routes and dosing schedules to balance effectiveness against side effects in these species.²³ The takeaway for humans is simply that the pharmacological principle behind medication abortion, blocking progesterone and then triggering uterine contractions, works across mammalian species. Aglepristone is not approved for use in people, and mifepristone is not commonly used in veterinary practice, so the two fields have diverged despite relying on the same biological mechanism.

1
Elsevier / Contraception. Mifepristone: where do we come from and where are we going? Clinical development over a quarter of a century
2
PubMed Central. Uses of Misoprostol in Obstetrics and Gynecology
3
PubMed Central. Efficacy and safety of medical abortion using mifepristone and buccal misoprostol through 63 days
4
PubMed Central. Effectiveness of medical abortion with mifepristone and buccal misoprostol through 59 gestational days
5
PubMed. Effectiveness and safety of misoprostol-only for first-trimester medication abortion: An updated systematic review and meta-analysis
6
PubMed Central. Efficacy of Misoprostol Alone for First-Trimester Medical Abortion: A Systematic Review
7
PubMed Central. Medication Abortion Safety and Effectiveness With Misoprostol Alone
8
PubMed. Methotrexate/misoprostol embryopathy: report of four cases resulting from failed medical abortion
9
Semantic Scholar. Successful Treatment of a Cervical Pregnancy by Single Dose Methotrexate and Vaginal Misoprostol
10
American Journal of Obstetrics and Gynecology. Early Medical Abortion Management of side effects and complications in medical abortion
11
PubMed. WHO multinational study of three misoprostol regimens after mifepristone for early medical abortion
12
PubMed. The mifepristone REMS: A needless and unlawful barrier to care
13
The Annals of Family Medicine. Remote Delivery in Reproductive Health Care: Operation of Direct-to-Patient Telehealth Medication Abortion Services in Diverse Settings
14
JAMA Internal Medicine. Mail-Order Pharmacy Dispensing of Mifepristone for Medication Abortion After In-Person Screening
15
PubMed Central. Primary care and abortion provider perspectives on mail-order medication abortion: a qualitative study
16
PubMed Central. Self-Managed Medication Abortion: History, Evidence, Models of Care, and Policy Considerations
17
PubMed. Self-managed abortion: A systematic scoping review
18
PubMed Central. A narrative review of illegal online pharmacies and contemporary issues with restricting FDA-approved medication access
19
The Cambridge Journal of Anthropology. It’s Not Mifepristone, But It’s Not Poison
20
Authorea. Effect of gene polymorphisms of multidrug resistance gene 1 and cytochrome P450 3A4 on the blood concentration and efficacy of mifepristone in medical abortion
21
PubMed Central. Effect of oral misoprostol, alone or in combination with aglepristone, on mid-term pregnancy termination in cats
22
PubMed. The intravaginal application of misoprostol improves induction of abortion with aglepristone
23
PubMed. Clinical evaluation of different applications of misoprostol and aglepristone for induction of abortion in bitches