Progestin-only pills contain one hormone, a progestin. They work by thickening the cervical mucus so sperm cannot reach the egg, and by making the lining of the uterus thinner. Sometimes they stop ovulation (the release of an egg). Among typical couples who use progestin-only pills about 5% will experience an accidental pregnancy in the first year. This is because some women do not take their pills correctly. But if these pills are used consistently and correctly, just one in 200 women will become pregnant. Complete information about this contraceptive is available from your clinician or the package insert accompanying the specific pills you are taking.
- There are no estrogen side effects with the mini-pill. These pills can be taken by women who have had side-effects or complications using estrogen-containing pills.
- The amount of progestin in mini-pills is less than in combined pills.
- Mini-pills are easier to take. You take exactly the same kind of pill every single day.
- Nursing mothers can take progestin-only pills, preferably after the baby is 6 weeks old.
- Menstrual irregularity is the most common problem with mini-pills. While there is less blood loss, bleeding may be at irregular intervals and there may be spotting between periods.
- Mini-pills tend to make periods short and scanty. You may go several months with no bleeding at all.
- You have to remember to take a pill every single day.
- The failure rate with mini-pills is a bit higher than with combined birth control pills. Some women use a backup method such as condoms while they are taking mini-pills.
- Progestin-only pills do not protect you from HIV or other infections. Use a condom if you or your partner may be at risk.
Where can I get mini-pills?
In the United States mini-pills require a prescription. You can get a prescription from your clinician, health department, or family planning clinic.
What if I have sex and don't use birth control?
For 72 hours AFTER unprotected sex, you can take emergency contraceptive pills to avoid becoming pregnant. For up to 7 days AFTER
unprotected sex, you can have an IUD put in. Not all clinicians know about emergency contraception. If you want more information or would like the phone numbers of clinicians near you who prescribe emergency contraception, CALL the toll-free hotline 1-888-NOT-2-LATE or 1-800-584-9911. Some of these sources of help are free.
These materials were written by Robert A. Hatcher, MD, MPH, Professor of Gynecology and Obstetrics, Emory University School of Medicine.