Progestin-only Contraceptives

What is the progestin-only birth control pill?

The mini-pill is a type of birth control pill that contains about half the amount of the hormone pro­gestin found in most combined oral contra­ceptives.  There is no estrogen in mini-pills. About 50% of women who take the mini-pill continue to ovulate.  The mini-pill prevents pregnancy by making cervical mucus thicker, which helps keep sperm from penetrating through the cervix to fertilize the egg.

The lower dose of the mini-pill means it is important you take your pill at the same time every day.  Some medical providers recommend you use a back-up method (like condoms) for first three cycles while using the mini-pill.

Who can use the mini-pill?

The progestin-only birth control pill (also known as the mini-pill or POPs) is a good option for people who are sensitive to the hormone estrogen.Combined oral contraceptive pills contain estrogen. Those who are breastfeeding or have a medical condition that prevents the use of estrogen-containing contraceptives can also use the mini-pill.

What are the benefits of using the mini pill?

  • Provides excellent protection against pregnancy when used correctly, with 2 to 9 pregnancies per 100 women each year
  • Helps with premenstrual symptoms (PMS) such as headaches and depression

The mini-pill offers other benefits, including some protection from:

Because the mini-pill doesn’t contain estrogen, those taking it may have a lower risk of blood clots and heart attacks com­pared to people using regular birth control pills.


What are the disadvantages of using the mini-pill?

  • Overall, the mini-pill is less effective than other types of birth control in protecting against pregnancy.  It is difficult for many women to take a pill at the same time every day.  Each year, 9% of women taking the mini-pill become pregnant.

What are the side effects and risks of using the mini-pill?

Side effects

The following symptoms can occur when one starts taking the mini-pill.  They are usually mild and go away sometime during the first few months of taking the pill.  If they do not stop or if they become too bothersome, talk to your provider about changing the way you take the pill or the kind of pill you take.

  • Spotting or “breakthrough bleeding” can occur in up to 25% of those taking the mini-pill
  • Not having a period altogether. The absence of a period is not harmful.  Just to be sure, if you miss your period, it is important for you to take a pregnancy test.
  • Headaches
  • Nausea
  • Weight changes
  • Mood changes
  • Cramping


More serious side effects are rare but may include:

  • An increase in cholesterol
  • Ectopic pregnancy (pregnancy outside the uterus)
  • Ovarian cysts.  The cysts usually disappear without treatment and rarely cause prob­lems.

Contact your doctor or local emergency room if you experience any of the following, which may be warning signs of a blood clot, heart attack or stroke:



  • Severe headache
  • Visual changes (flashing lights in the eyes, blurring and/or partial loss of vision)
  • Numbness or tingling in the face, an arm, leg, hand or foot
  • Sharp pain in the chest, shortness of breath, or coughing up blood (these symptoms may indicate possible clots in the lungs)
  • Severe leg pain (possible clot in the leg)
  • Crushing chest pain or heaviness (possible heart attack)
  • Severe abdominal pain

Other considerations

Certain drugs taken at the same time as birth control pills can make them less effec­tive. Such drugs also may cause an in­crease in breakthrough bleeding.  This more commonly occurs with medications for epilepsy and the anti-tuberculosis drug, rifampin.  If another medication is pre­scribed while you are taking the pill, talk with your health care provider and your pharmacist about possible problems from taking these medications together.

How do I take the mini-pill?

Instruction for use may vary slightly from one brand to another.  You should read and follow the instructions that come with your pill.  With all brands of pills, it is recommended that you:

  • Keep a back-up birth control method such as condoms or a diaphragm available. You will need to use your back-up method for at least the first seven days.
  • Take one pill each day until you finish your pill pack.  Then start your new pack the next day. Never miss a day. Find a regular time each day you will remember to take the pill.
  • Take your pill as close to the same time every day as possible.

What do I do if I miss a pill?

If you are late or miss taking your pills, take the missed pill as soon as you re­member that you missed it.  Take your scheduled pill at the regular time even if that means taking two pills in one day.  If you are more than three hours late taking the mini pill, there is a good chance you could become pregnant.

Use a back-up method for the next 48 hours.  If you’ve had unprotected sex recently, you may want to consider taking emergency contraception (the morning after pill). If your menstrual period does not begin within 4-6 weeks, see your clinician for a pregnancy test.

Additional information provides information about many different birth control methods

Planned Parenthood’s website offers information on the effectiveness of different kinds of birth control methods

If you are a UW student or an established Hall Health patient, you may call Hall Health’s Consulting Nurse service for further information.


Authored by: Hall Health Center Women’s Health Clinic staff

Reviewed by: Hall Health Center Women’s Health Clinic staff, January 2014