Breastfeeding and the Mini-Pill

The progestin-only mini-pill is an effective form of birth control. If you are a new parent, you may be concerned about whether the mini-pill is safe and effective while breastfeeding. While the mini-pill is not as effective overall as contraceptive pills that contain estrogen and progestin, breastfeeding people generally have lower fertility, making it a good option for some new parents.

The hormones from the mini-pill do pass into breast milk in small amounts, but there are no known harms to the breastfeeding child. Some people choose to change to a combination pill when they are done breastfeeding. It’s important to note that while exclusive breastfeeding may offer birth control for a short time, it only works under specific circumstances, and is not singularly a reliable method of birth control.

What Is the Mini-Pill?

The mini-pill contains progestin, which is a form of progesterone, a reproductive hormone. The mini-pill works to prevent pregnancy by thickening cervical mucous and thinning the lining of the uterus known as the endometrium. These changes make it difficult for an egg to be fertilized or implanted. In addition, the mini-pill stops ovulation in 60% of people who take it—although 40% of people on the mini-pill will continue to ovulate.

Like other contraceptive pills, the mini-pill comes in packs of 28. To be effective, they need to be taken at the same time every day. Unlike combination pills, however, all pills in the pack contain progestin (there are no placebo pills). So while most people who take combination pills will continue to experience a "period" (a withdrawal bleed) each much during the placebo week, people who take the mini-pill may experience lighter periods or even stop having menstrual cycles while taking the mini-pill. 

Mini-Pill Effectiveness

With perfect use, the mini-pill prevents pregnancy more than 99% of the time in the first year of use. However, most people do not use birth control perfectly every time. When accounted for typical use, meaning missed or late doses, 9% of people will get pregnant in the first year of using the mini-pill.

Even if you miss just one pill, you'll need to use a backup method of birth control, like condoms, for 48 hours until you are back on schedule with the pills. If you made a mistake and then you don't have a period within 45 days, you could be pregnant.

If you missed more than two pills, there is a chance you will ovulate, and you need to use a backup method for two weeks. You will need to rule out pregnancy after a couple of weeks.

If you're in a country besides the United States, the mini-pill you've been prescribed might be different. If you miss a pill, you might need to use a backup method for up to two weeks. Be sure to contact your healthcare provider or read the package insert to be sure.

Mini-Pill Safety While Breastfeeding

The mini-pill is often prescribed for breastfeeding people because it does not appear to affect breast milk the way that combination oral contraceptives can. That said, you may want to wait to start progestin-based contraception until at least a couple of days after you give birth, as a drop in progesterone is necessary following birth for lactogenesis to occur.

Research indicates that when progestin-only contraception is initiated after the initial postpartum period, no adverse effects on breastfeeding were noted through 12 months of age. One study found that those who used progestin-only contraception were more likely than those who used combined hormonal contraceptives to reach their breastfeeding goals by four months.

Small amounts of hormones pass through breast milk, but they have not been found to be harmful to infants. Researchers have found no adverse effects on infant immunoglobulins or infant sex hormones through 12 months of age.

Mini-Pill Risks and Side Effects

The mini-pill is considered a safe birth control option for breastfeeding parents, but like all medications, it does carry some risks. Certain people should not take the mini-pill.

Talk to your doctor if you:

• Have allergies to medications, progestins, aspirin, or yellow food coloring
• Take prescription or OTC medication
• Smoke
• Are or might become pregnant
• Have had breast cancer
• Have liver tumors, hepatitis, or cirrhosis

Some known side effects associated with the mini-pill include:

• Irregular menstrual periods
• Headache 
• Breast tenderness
• Nausea
• Dizziness
• Acne
• Weight gain
• Hair growth

Some of the known side effects of the mini-pill are also symptoms of pregnancy (such as dizziness, nausea, changes in your breasts, weight, mood, sex drive, and menstrual flow). It is not uncommon for people who exclusively breastfeed to experience amenorrhea (the absence of a menstrual period), so attention to other symptoms that could be side effects or pregnancy signs is important while breastfeeding.

Before you dismiss any of your symptoms as side effects from your birth control, it's wise to take a home pregnancy test. But even if it's negative, know that it's possible to get a negative result and still be pregnant. You may want to visit your doctor to rule out pregnancy with certainty.

A Word From Verywell

Although exclusive breastfeeding does offer some protection from pregnancy, it is only effective under certain conditions. Breastfeeding alone is not considered an effective form of birth control for most people. 

If you are looking for a more effective form of birth control while breastfeeding, the mini-pill may be a good option to discuss with your doctor. Not everyone is a good candidate for the mini-pill, though, so be sure to disclose your complete health history with your doctor before you begin taking a progestin-based pill.