Updated December 16, 2014.

Definition of Progestin-Only Pills:

These pills are a type of oral contraceptive (birth control pill) that contain a synthetic form of the progesterone hormone and have no estrogen.

Also Known As:

The Mini-Pill and POP (Progestin-Only Pill)

Progestin-Only Pill Pack Size:

The Mini-Pill is only available in a 28-day pack. A woman will take a pill every day for the 4 week cycle, and all 28 pills are considered active.

Active pills contain the hormone that prevents a woman from becoming pregnant. Menstruation usually occurs during the fourth week even though the woman is still taking active pills.

Comparison to Combination Pills:

Progestin-only pills are slightly less effective than the combined pill; however, they also tend to cause less side effects.

  ---> Side Effects of Progestin-Only Pills

How They Work:

POP’s may prevent a woman's body from releasing an egg during her monthly menstrual cycle. However, ovulation may not be always be stopped by progestin-only pills.

  ---> How Progestin-Only Pills Work

Who Should Use Progestin-Only Pills?

Because mini-pills do not contain estrogen, they can be a good alternative for women who can not use combination hormonal contraceptives. These include:

• Cigarette smokers over the age of 35
• Women with a history of blood clots
• Women with high blood pressure
• Women who experience extreme migraine headaches

Additionally, progestin-only pills can be prescribed for breastfeeding mothers since the hormone will not negatively affect milk production or harm a baby during nursing.

In fact, studies have shown that POP’s may actually help increase the amount of milk produced.

Progestin Types:

There are typically 2 different types of progestin hormones found in mini-pills that mimic the natural hormone of progesterone.

Progestin-only pills can contain the following synthetic progestin:

1. Norethindrone - the following brand name pills contain this hormone:

• Ortho Micronor
• Errin
• Aygestin
• Nor-QD
• Camila
• Jolivette
• Nora-BE

2. Norgestrel - the following brand name pill contains this hormone:

• Ovrette