Breast-feeding and medications: What's safe?

Wondering about breast-feeding and medications? Know how medications can affect your breast milk and which drugs are safe to take.

By Mayo Clinic Staff

If you're breast-feeding, you know you're giving your baby a healthy start. However, if you need to take medication while you're breast-feeding, you might have questions about the possible impact on your breast milk.

Here's what you need to know about medications and breast-feeding.

Do all medications pass into breast milk?

Almost any drug that's present in your blood will transfer into your breast milk to some extent. However, most medications do so at low levels and pose no real risk to most infants. There are exceptions, though, in which drugs can become concentrated in breast milk. As a result, every medication must be considered separately.

Does my baby's health and age influence how he or she might be affected by exposure to medication in my breast milk?

Yes. Exposure to medication in breast milk poses the greatest risk to premature babies, newborns, and babies who are medically unstable or have poorly functioning kidneys.

The risk is lowest for healthy babies 6 months and older, who can metabolize drugs efficiently. Women who breast-feed more than one year after childbirth often produce relatively smaller quantities of milk. This reduces the amount of medication transferred to breast milk. Also, medications used in the first three to four days after childbirth transfer at very low levels to an infant, due to the limited volume of breast milk you're producing.

Should I stop breast-feeding while taking medication?

Most medications are safe to take while breast-feeding. Also, the benefit of continuing to take a medication for a chronic condition while breast-feeding often outweighs any potential risks.

Still, a few medications aren't safe to take while breast-feeding. If you currently take a medication that could be harmful to your baby, your health care provider might be able to recommend a safe alternative medication. Or, he or she might recommend breast-feeding when the medication is at a low level in your breast milk.

In rare cases, your health care provider might recommend that you stop breast-feeding temporarily or permanently — depending on how long you need to take the medication. If you have advanced notice, pump in addition to breast-feeding and store surplus expressed milk for use during that time. If you need to stop breast-feeding only temporarily, use a double electric breast pump to keep up your milk supply until you're able to breast-feed again. Discard the milk you pump while you're taking the medication.

If you're not sure if a medication is compatible with breast-feeding, pump, clearly label and store expressed breast milk in a separate area until you can check with your health care provider.

If you need to stop breast-feeding permanently — which is unusual — ask your health care provider about weaning and to help you choose an infant formula that will meet your baby's needs.

July 30, 2015 See more In-depth