Plan B and Breastfeeding
Although the hormones in birth control pills pass through breast milk, it is generally considered safe to use Plan B while breastfeeding. Plan B and other progestin-only contraceptives are not likely to affect the quantity and quality of breast milk. However, if you are breastfeeding, you should talk to your healthcare provider before using Plan B.
Plan B One-Step™ (levonorgestrel) is an emergency contraceptive pill (a "morning-after pill") that is used to prevent pregnancy when used within 72 hours after unprotected sex. In general, Plan B is considered safe for use in women who are breastfeeding, although it is a good idea to check with your healthcare provider first.
Plan B contains levonorgestrel, a progestin hormone that is also used in regular birth control pills. Studies have shown that the hormones in birth control pills do pass through breast milk, although usually in low amounts. These amounts are probably too low to cause significant or long-lasting problems in nursing infants. Progestin-only contraceptives (including Plan B) are not likely to affect the quantity and quality of breast milk.
You should talk with your healthcare provider about Plan B and breastfeeding. Each woman's situation is different, and you and your healthcare provider understand your situation best. After considering what you want and expect, as well as your current health situation, the two of you can make a shared decision about Plan B and breastfeeding that is right for you.