Cassie Health Center for Women

Gynecology >> Oral Progesterone

Progesterone-Only Birth Control

Progesterone-only birth control pills (POPs), also called the "mini pill", contains only half of the ingredients found in a regular birth control pill.

Regular birth control pills contain both estrogen and progesterone. Estrogen-containing pills can increase the risk of clotting in women with high blood pressure, diabetes, migraine, clotting disorders and smokers. These women are encouraged to use products without estrogen.

Estrogen can also decrease the production of milk in breastfeeding women. Women who want to continue to breastfeed should avoid products containing estrogen.

A regular birth control pill is 93-99% effective in the first year of use and 97-99% in subsequent years of use.

A progesterone-only birth control pill is as effective: 97-99%

With all birth control pills, effective pregnancy prevention relies upon the regular, daily use of the product.

The brand name mini pill is called Micronor. Many generics are available.

When you open the pack of Micronor you will immediately notice that every pill is the same color. This is because every pill has medicine in it. There is no break for your period.

Therefore, the most common complaint of women using Micronor is irregular periods. Not heavy bleeding, but possibly unpredictable bleeding. Most women experience lighter periods over months of use and do develop some type of pattern to their periods.

Some women will experience no period after many months of taking progesterone-only birth control pills. This is not harmful. Periods will return when the pill is discontinued.

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