How Soon Does the Abortion Pill Work?

When Will the Bleeding Start? How Long Does It Take to Complete a Medical Abortion?

The abortion pill starts taking effect almost immediately, even though it may not be felt right away.

The active ingredient of Plan C (mifepristone) blocks the absorption of the pregnancy hormone, progesterone, causing the embryo to no longer be supplied with nutrients and succumb to starvation. This usually happens within 48 hours of taking the first pill.

Since mifepristone alone does not usually lead to the expulsion of the embryo, another medication containing the active ingredient misoprostol (e.g., Cytotec® or MisoOne®) is taken one to three days later. Misoprostol is a synthetically produced prostaglandin that induces uterine contractions. This medication usually completes the abortion process by emptying the uterine contents.

The onset of bleeding varies greatly. In rare cases, the uterus, including the embryo, is emptied upon taking the first pill (Mifeprex®). More commonly, uterine contractions and bleeding begin within hours after taking the second medication. While the expulsion phase is often completed within 4-5 hours, the timing, intensity, and duration of cramping and bleeding vary greatly. Therefore, medical support must be available within a two-hour drive, and a post-abortion check-up is recommended.

Medical abortions are completed in several stages and can extend over about two weeks due to post-abortion bleeding. Abortion pill experiences are unique to each woman, including the time that is needed to emotionally process the abortion.