The abortion pill is actually two different medications taken one to two days apart. The first blocks the hormone that sustains a pregnancy, and the second triggers the uterus to empty. This two-step process is approved for use up to 10 weeks (70 days) of gestation, and roughly 5.9 million women in the U.S. have used it since it was first approved in 2000.
Step One: Blocking Progesterone
The first medication is a single 200 mg tablet taken by mouth. It works by binding to the same receptors in the uterus that progesterone normally attaches to. Progesterone is the hormone responsible for maintaining the uterine lining and supporting an early pregnancy. When the medication occupies those receptors, progesterone can no longer do its job.
Without progesterone signaling, the nutrient-rich lining of the uterus begins to break down. Blood vessels that supply the lining are damaged, cutting off the support system the embryo depends on. The medication also directly promotes uterine contractions, which sets the stage for the second step. After taking this first pill, most people don’t notice dramatic changes right away, though some light bleeding or nausea can occur.
Step Two: Emptying the Uterus
Between 24 and 48 hours later, you take four tablets of the second medication. These are placed two in each cheek pouch, held there for 30 minutes, and then any remaining fragments are swallowed with water. This drug mimics a natural compound called prostaglandin, which tells the uterus to contract.
Once the second medication is absorbed, it causes strong, rhythmic contractions that expel the pregnancy tissue. It also softens and opens the cervix to allow the tissue to pass. This is the step where the physical process of the abortion happens. Most people begin bleeding heavily within one to four hours of taking these tablets, and will pass clots and tissue during that time.
What Bleeding and Cramping Feel Like
The cramping after the second medication is typically more intense than a normal period. Many people describe it as strong, wave-like pain in the lower abdomen, sometimes accompanied by nausea, diarrhea, or chills. Over-the-counter pain relievers and a heating pad help manage the discomfort. The worst of the cramping usually passes within a few hours as the tissue is expelled.
Bleeding and spotting are normal for an average of 9 to 16 days afterward, and can last up to 30 days. The heavy bleeding tapers off relatively quickly, but lighter spotting may continue for weeks. A useful threshold to keep in mind: soaking through two or more full-size pads per hour for two consecutive hours is considered excessive and warrants immediate medical attention.
How You Know It Worked
Two weeks after the procedure, you take a low-sensitivity pregnancy test at home to confirm the pregnancy has ended. A regular high-sensitivity test can stay positive for weeks due to lingering pregnancy hormones, so the specific type of test matters.
Signs that the medication may not have worked include no bleeding at all within 24 hours of taking the second set of pills, a positive pregnancy test at the two-week mark, or persistent pregnancy symptoms like nausea and breast tenderness. If the medication fails, a surgical procedure or a repeat dose may be needed to complete the process. Failure rates rise as gestational age approaches the 10-week limit.
Who Should Not Take It
The abortion pill is not appropriate for everyone. It will not work for an ectopic pregnancy (one that has implanted outside the uterus), and taking it in that situation could delay treatment for a potentially dangerous condition. Other contraindications include:
- An IUD in place. The device must be removed before starting the medication.
- Bleeding disorders or blood-thinning medications. These increase the risk of heavy, uncontrolled bleeding.
- Chronic adrenal failure or long-term steroid use. The first medication can interfere with adrenal hormone function.
- Allergy to either medication.
- A rare condition called porphyria.
How Common Are Serious Complications
Serious complications from medication abortion are uncommon relative to the number of people who use it. Out of approximately 5.9 million uses in the U.S. through the end of 2022, the FDA documented roughly 1,049 hospitalizations (excluding deaths), 604 cases requiring blood transfusions, and 418 infections across the entire reporting period. Of those infections, 75 were classified as severe.
Those numbers come with an important caveat: the FDA notes that not every adverse event can be definitively attributed to the medication itself, since reporting gaps make it difficult to rule out other contributing factors. Still, the overall rate of serious complications represents a small fraction of total uses. The most common issue that requires medical intervention is excessive bleeding.
Timeline at a Glance
The entire process unfolds over about two weeks. Day one, you take the first pill. One to two days later, you take the second set of pills and experience the active cramping and bleeding, which is most intense for several hours. Over the following days, bleeding gradually decreases. At the two-week mark, a pregnancy test confirms the process is complete. Most people return to normal daily activities within a day or two of the heaviest bleeding, though everyone’s recovery pace is different.