Breastfeeding and Medication: What’s Safe and What to Avoid

When you’re breastfeeding and medication, the practice of taking pharmaceuticals while nursing an infant. Also known as medication use during lactation, it’s not about avoiding drugs altogether—it’s about choosing the right ones at the right time. Many new parents assume any pill they take will reach their baby through breast milk, but the truth is more nuanced. Most medications enter breast milk in tiny amounts, and even fewer cause harm. The real question isn’t whether drugs get into milk—it’s whether they matter.

Think of breastfeeding and pain relief, the use of analgesics like acetaminophen or ibuprofen while nursing. Acetaminophen is widely recommended because less than 1% of the dose passes into milk, and it’s been studied in thousands of nursing mothers. Ibuprofen is similarly low-risk, with minimal transfer and no documented effects on infants. But contrast that with breastfeeding and antidepressants, the use of SSRIs or other psychiatric drugs during lactation. Some, like sertraline, have strong safety data and are often first-line choices. Others, like certain benzodiazepines or fluoxetine, can build up in infants and cause drowsiness or feeding issues. It’s not that one is good and the other bad—it’s about matching the drug to the baby’s age, health, and your treatment needs.

What about antibiotics? Many are fine. Penicillin, amoxicillin, and cephalexin rarely cause problems. But tetracycline can stain developing teeth, and some sulfa drugs can trigger jaundice in newborns. Even drugs in breast milk, pharmaceutical compounds transferred from mother to infant via lactation aren’t all bad—sometimes they’re protective. For example, low-dose aspirin in breast milk may reduce the risk of SIDS. The key is consistency: if you take a medication daily, your baby gets a steady, low dose. A one-time dose? Even less concern. But never assume safety just because something is "over-the-counter." Cold medicines often contain pseudoephedrine, which can dry up your milk supply, or diphenhydramine, which can make your baby sleepy and fussy.

There’s no universal list of safe and unsafe drugs. What works for one mom might not work for another. Your baby’s age matters—newborns process drugs slower than six-month-olds. Your dose matters. Your health condition matters. And your doctor’s familiarity with lactation pharmacology matters more than you think. Many providers still default to "avoid everything," but that’s outdated. The American Academy of Pediatrics and LactMed database show that over 90% of medications are compatible with breastfeeding when used appropriately.

You don’t need to stop breastfeeding to treat depression, infection, or pain. You just need to know which meds to pick—and which to skip. Below, you’ll find real-world examples from studies and clinical reports that show exactly what’s been proven safe, what’s risky, and what’s still unclear. No fluff. No fearmongering. Just the facts you need to make confident choices while keeping your baby healthy.