Birth control pills - progestin only

Birth control pills help keep you from getting pregnant. The pills with only progestin come in 28-day packs. Every pill is active. Each has only progestin and no estrogen. These types of birth control pills often are used for women who have medical reasons that prevent them from taking a combination oral contraceptive pill (pills that contain progestin and estrogen). Some of the reasons to take progestin-only birth control pills include:

• History of migraine headaches
• Currently breastfeeding
• History of blood clots

Progestin-only pills are very effective if taken correctly.

Progestin-only pills work by making your mucus too thick for sperm to move through.

You may start taking these pills any time in your menstrual cycle.

Protection from pregnancy begins after 2 days. If you have sex within the first 48 hours after your first pill, use another birth control method (condom, diaphragm, or sponge). This is called backup birth control.

You must take the progestin-only pill at the same time every day.

Never miss a day of taking your pills.

When you have 2 packs of pills left, call your health care provider for an appointment to get a refill. The day after you finish a pack of pills you need to start a new pack.

With these pills you may:

• Not get periods
• Bleed a bit on and off through the month
• Get your period in the fourth week

If you do not take the progestin pill on time, your mucus will start to thin and you could become pregnant.

When you realize you missed your pill, take it as soon as possible. If it is 3 hours or more since it was due, use a backup birth control method for the next 48 hours after taking the last pill. Then take your next pill at the usual time. If you had sex in the last 3 to 5 days, consider asking your provider for emergency contraception. If you have any questions or concerns, call your provider.

If you vomit after you take a pill, take another pill as soon as possible, and use a backup birth control method for the next 48 hours.

You may decide to stop taking birth control pills because you want to get pregnant or you want to change to another birth control method. Here are some things to expect when you stop taking the pill:

• You should get your period 4 to 6 weeks after you take your last pill. If you do not get your period in 8 weeks, contact your provider.
• Your period may be heavier or lighter than usual.
• You may have mild spotting of blood before you get your first period.
• You might become pregnant right away.

Use a backup method of birth control, such as a condom, diaphragm, or sponge, if:

• You take a pill 3 hours or more after it was due.
• You miss 1 or more pills.
• You are sick, throwing up, or have loose stools (diarrhea). Even if you take your pill, your body may not absorb it. Use a backup method of birth control, and call your provider.
• You are taking another medicine that may prevent the pill from working. Tell your provider or pharmacist if you take any other medicines, such as antibiotics, seizure medicine, medicine to treat HIV, or St. John's wort. Find out if what you take will interfere with how well the pill works.

Contact your provider if:

• You have swelling in your leg.
• You have leg pain.
• Your leg feels warm to the touch or has changes in skin color.
• You have fever or chills.
• You are short of breath and it is hard to breathe.
• You have chest pain.
• You cough up blood.

Mini-pill; The pill - progestin; Oral contraceptives - progestin; OCP - progestin; Contraception - progestin; BCP - progestin

Allen RH, Kaunitz AM, Hickey M, Brennan A. Hormonal contraception. In: Melmed S, Auchus, RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 18.

Glasier A. Contraception. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 134.

Isley MM. Postpartum care and long-term health considerations. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 8th ed. Philadelphia, PA: Elsevier; 2021:chap 24.

Updated by: John D. Jacobson, MD, Department of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.