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Facts About...

Progestin-Only Pill


What is it?

The progesterone-only pill, also called the “mini-pill” contains only one hormone called progestin. The progestin-only pill helps prevent pregnancy in women who are unable to take estrogen. Progestin helps prevent pregnancy by thickening the mucous in the vagina, which keeps the sperm from getting to the eggs. It stops the eggs from leaving the ovaries in about half of users. It can also change the lining of the uterus, making it harder for an egg to attach to the wall of the uterus. The progestin-only pill is taken at the same time every day for 28 days with no pill-free period.

How effective is it?

Less than 1 out of 100 women will get pregnant every year if they always take the pill each day as directed. When the pill is not taken as directed, 5-10 out of every 100 women are at risk of becoming pregnant.

What are the side effects of this method?

Irregular bleeding, changes in menstrual flow (lack of period), headache, breast tenderness, nausea, mood changes, acne and dizziness are experienced by some women. Most side effects disappear with continued use.

What are the benefits?

Progestin-only pills provide a safe alternative to the combined contraceptive pill for women who are unable to take estrogen. Benefits of the "mini-pill" can include: effective and reversible birth control, decreased bleeding and cramping, and decreased frequency and severity of migraine headaches. The progestin-only pill can be started by postpartum women any time after childbirth.

What are the limitations?

Progestin-only pills contain one hormone so they must be taken at the same time every day. If a dose is taken 3 or more hours late, a back-up form of protection (condoms), must be used for the next 48 hours to decrease the risk of pregnancy. There is a higher risk of ectopic pregnancy (pregnancy outside of the uterus) if you become pregnant while on progestin-only pills. If you become pregnant or complain of pain in your lower abdomen while on a progestin-only pill, an ectopic pregnancy must be ruled out.

What are the effects on breastfeeding?

The progestin-only pill can be used in breastfeeding women and should not have an effect on breast milk supply.

You should know…

There are other forms of progestin-only birth control options available such as intrauterine devices if you have problems remembering to take your pill. If you have side effects that are long lasting, you should talk with your health care provider, as a different type of birth control may be better for you.

Stopping and starting the pill repeatedly (pill breaks) is not recommended. This places women at risk of unplanned pregnancy and irregular periods.

The pill does not affect your ability to have children in the future.

The pill does not prevent the transmission of sexually transmitted infections, including HIV/AIDS. Condoms should always be used during sexual activity.

Contact your health care provider immediately if you experience any of the following while taking the pill: sudden and severe abdominal pain, yellowing of the skin or eyes, or any abnormal or bothersome symptoms.

March 20, 2017