Loratadine and Breastfeeding: What You Need to Know

When you're nursing, every pill you take matters. loratadine, a second-generation antihistamine used for allergies like hay fever and hives. It's known for being non-drowsy and widely available over the counter, but that doesn't mean it's automatically safe while breastfeeding. Many moms worry: will this drug pass into my milk? Will it make my baby sleepy or irritable? The good news is, research shows loratadine is one of the safer choices among antihistamines for nursing mothers.

Unlike older antihistamines like diphenhydramine (Benadryl), which cross into breast milk more easily and can cause anticholinergic effects, side effects like dry mouth, constipation, and urinary retention in babies, loratadine has very low transfer rates. Studies tracking milk levels found only tiny amounts—less than 1% of the mother’s dose—end up in breast milk. That’s not enough to cause sedation or feeding problems in most infants. The American Academy of Pediatrics even lists loratadine as compatible with breastfeeding.

Still, not all babies react the same. Some might be extra sensitive, especially newborns or those with liver issues. Watch for unusual sleepiness, poor feeding, or irritability in the first few days after starting the medication. If you notice anything off, talk to your doctor. You can also try taking the dose right after nursing, so the lowest amount is in your milk when your baby feeds next.

What about other allergy meds? If loratadine doesn’t work well for you, cetirizine is another low-risk option with similar data. Avoid first-gen drugs like chlorpheniramine unless absolutely necessary—they’re more likely to affect your milk supply or your baby’s alertness. And remember, just because a drug is sold as "safe" doesn’t mean it’s right for everyone. Your body, your baby, your choices.

There’s a lot of conflicting advice out there about what you can take while nursing. That’s why it’s important to rely on real data, not rumors or fear. Below, you’ll find detailed breakdowns of how antihistamines behave in the body, what other medications pose risks during lactation, and how to spot hidden dangers like anticholinergic side effects that even doctors sometimes miss.