Can You Take Plan B While Breastfeeding? Emergency Contraception and Birth Control While Nursing

A broken condom, a missed pill, or simply realizing your fertility might be back sooner than you expected: if you need emergency contraception while you’re nursing, the good news is that it doesn’t have to interrupt breastfeeding.

This guide covers the three emergency options available in the US (Plan B and other levonorgestrel pills, ella, and the copper IUD) and then the birth control methods you might use going forward, with how each one fits with breastfeeding. It’s based on the CDC’s U.S. Medical Eligibility Criteria for Contraceptive Use (U.S. MEC, 2024), LactMed, product labels and ACOG. For other medicines, see our hub on what’s safe while breastfeeding.

How the CDC rates methods while breastfeeding

The U.S. MEC sorts each method into one of four categories for a given situation, such as “breastfeeding, 30 to 42 days after birth.” The CDC defines them as:

Category	Meaning
1	No restriction for use of the method
2	Advantages generally outweigh theoretical or proven risks
3	Theoretical or proven risks usually outweigh the advantages
4	Unacceptable health risk; the method should not be used

Plan B and other levonorgestrel pills

Plan B One-Step contains one tablet of levonorgestrel 1.5 mg. The Drug Facts label says to take it as soon as possible within 72 hours (3 days) after unprotected sex. It won’t work if you’re already pregnant, it isn’t for regular birth control, and if you vomit within 2 hours of taking it you should call a healthcare professional about whether to take another dose. The label’s warnings don’t mention breastfeeding.

What the breastfeeding sources say:

• CDC: levonorgestrel emergency pills are category 1 while breastfeeding. The CDC notes that one study found levonorgestrel passes into breast milk in minimal quantities, and that breastfeeding outcomes don’t seem to differ between women who took it and those who didn’t.
• LactMed: emergency (postcoital) levonorgestrel appears to have no long-term adverse effects on breastfeeding or the baby.

So you can take Plan B, or a generic levonorgestrel pill, and keep breastfeeding as usual.

Ella (ulipristal)

Ella is a prescription emergency pill. The ella label says to take one 30 mg tablet as soon as possible within 120 hours (5 days) after unprotected sex.

• CDC: ulipristal is category 1 while breastfeeding. It’s present in milk in small amounts, and there’s no evidence about its effects on breastfed babies.
• The label: a fully breastfed baby would get roughly 0.8% of the mother’s weight-adjusted dose on the first day and about 1% over 5 days. It says there’s no information on effects on the baby or on milk production, and advises weighing the benefits of breastfeeding against your need for the medicine.
• LactMed: amounts in milk are low, and taking ulipristal is not a reason to stop breastfeeding. Some older sources said to withhold breastfeeding for 24 hours after a dose, but LactMed says that’s no longer a requirement under the current FDA-approved labeling.

One practical point: the ella label says to start or restart hormonal birth control no sooner than 5 days after taking ella, and to use a barrier method such as condoms until your next period.

The copper IUD as emergency contraception

The CDC says a copper IUD can be placed within 5 days of unprotected sex as emergency contraception, and it’s category 1 while breastfeeding. LactMed calls it the most effective emergency contraceptive when inserted within 5 days, and says it’s acceptable as long-term birth control while breastfeeding because it doesn’t affect lactation or the copper level in milk. If you’d like a method that keeps working afterward, ask whether you can get one placed quickly.

Can breastfeeding itself prevent pregnancy?

Sometimes, but only under strict conditions. The CDC says the lactational amenorrhea method (LAM) protects you only when all three of these are true:

1. Your periods haven’t come back.
2. You’re fully or nearly fully breastfeeding, with no more than 4 hours between feeds during the day and 6 hours at night.
3. Your baby is less than 6 months old.

ACOG adds that ovulation usually happens about 2 weeks before a period, so you can get pregnant before your first postpartum period, and that it’s unclear whether pumping instead of nursing makes LAM less effective. If any of the three conditions has changed, LAM no longer protects you, which is often why emergency contraception comes up. Our guide on getting pregnant while breastfeeding explains how fertility returns, and our article on your period while breastfeeding covers what to expect.

Ongoing birth control while breastfeeding

ACOG says all birth control methods are safe to use while breastfeeding, and that only a few aren’t recommended in the first weeks because of a very small risk to milk supply. Here’s how the CDC’s 2024 summary table rates the hormonal methods for breastfeeding parents (lower is better):

Time since birth	Implant	Shot (DMPA)	Progestin-only pill	Combined pill, patch, ring
Under 21 days	2	2	2	4
21 to under 30 days	2	2	2	3
30 to 42 days, other clot risk factors	1	2	1	3
30 to 42 days, no other clot risk factors	1	1	1	2
Over 42 days	1	1	1	2

For IUDs, the CDC rates both copper and hormonal IUDs category 2 if placed from delivery up to 4 weeks after birth, and category 1 from 4 weeks on, whether or not you breastfeed.

Progestin-only methods

LactMed says that although non-hormonal methods are preferred during breastfeeding, progestin-only methods are considered the hormonal contraceptives of choice, and fair-quality evidence shows that levonorgestrel doesn’t harm milk composition, the baby’s growth and development, or milk supply. expert opinion holds that their risks are usually acceptable for nursing mothers at any time after birth.

• Progestin-only pills. ACOG says they can be started right after childbirth. The label for Opill, an over-the-counter progestin-only pill, says it is safe and effective in breastfeeding women.
• The implant. ACOG says it can be inserted right after a vaginal or cesarean birth. LactMed cites a review estimating a risk of lactation suppression of about 0.9% with the etonogestrel implant, and a meta-analysis finding that immediate insertion didn’t interfere with milk coming in or reduce breastfeeding at 3 or 6 months.
• The shot (DMPA). The timing of the first shot is debated. LactMed says the product labeling advises starting no sooner than 6 weeks after birth, the World Health Organization recommends the same, and studies of earlier use are of low or variable quality.
• Hormonal IUD. LactMed says there are no reports of adverse effects in breastfed babies with progestin-only methods. Small studies disagree on whether insertion immediately after birth affects breastfeeding.

Copper IUD

The copper IUD has no hormones and doesn’t affect breastfeeding. ACOG says IUDs can be placed right after birth or at your postpartum visit, and that about 5 in 100 users have the IUD come out in the first year, which is more common when it’s placed right after delivery. LactMed notes that breastfeeding may increase the risk of perforation during insertion compared with not breastfeeding, though the absolute risk is low.

Combined methods with estrogen

The combined pill, patch and ring contain estrogen, and that’s where the supply concern lies. LactMed says a decrease in milk supply can happen over the first few days of estrogen exposure, that ethinyl estradiol at more than 30 mcg a day can suppress lactation, and that cases of lower supply have been reported at 30 mcg. The effect likely depends on the dose and how soon after birth you start.

The CDC classification for breastfeeding parents is category 4 before 21 days (mainly because of blood clot risk after birth), category 3 from 21 to under 30 days, and category 2 after 42 days. The CDC notes that studies conflict on whether these methods affect how long or how exclusively people breastfeed. ACOG advises avoiding them for the first 4 to 6 weeks, until breastfeeding is established. If you start one and your supply seems to drop, talk to your provider about switching, and see our guide on how to increase milk supply.

When to call a doctor or lactation consultant

Contact a healthcare provider:

• if you vomit within 2 hours of Plan B or within 3 hours of ella, since you may need another dose,
• if you think you might be pregnant after taking emergency contraception,
• if you need emergency contraception and want a copper IUD, as soon as possible within the 5-day window,
• if your milk supply drops after starting a new hormonal method,
• to choose ongoing birth control that matches your breastfeeding plans. ACOG suggests choosing while you are still pregnant, but it is never too late to ask.

Call your baby’s doctor if your baby isn’t feeding well, has fewer wet diapers or isn’t gaining weight as expected. If you want help protecting your supply while you sort out birth control, an IBCLC can help; our breastfeeding support page lists where to find one.