Is Prilosec (Omeprazole) Safe While Breastfeeding?

What does the evidence say about Prilosec while breastfeeding?

1. Limited data suggest that a dose of 20 mg of omeprazole or esomeprazole daily results in low levels of the medication in breast milk, amounts that aren't expected to be harmful to a nursing infant. 1
2. In one study, a mother taking 20 mg of omeprazole daily had undetectable milk levels for the first 90 minutes after dosing, then a peak of 20 mcg per liter three hours later, an infant dose estimated at less than 1% of the mother's weight-adjusted dose. 2
3. As a class, proton pump inhibitors like omeprazole are broken down by the baby's own stomach acid and not meaningfully absorbed, and these medications are sometimes given directly to infants with reflux, which is part of why they're considered compatible with breastfeeding. 3
4. In one case report, an infant whose mother took 20 mg of omeprazole daily throughout breastfeeding for three months remained well through 12 months of age. 2
5. Famotidine (Pepcid), another heartburn medication used while breastfeeding, also passes into breast milk in small amounts and has been given directly to newborns at higher doses than what's found in breast milk, without expected problems for nursing infants. 4

How Prilosec changes by nursing stage

• Early weeks. If heartburn continues right after delivery, the same omeprazole many people already take in pregnancy is considered compatible with breastfeeding, with no need to pump and dump.
• Established nursing. If you're taking omeprazole regularly while nursing, the small amount that reaches breast milk is further broken down by your baby's own stomach acid, which is part of why it's considered low-risk for a nursing infant.
• Weaning. If reflux persists well into the postpartum months, it's worth a check-in with your provider on whether ongoing omeprazole is still the right fit, rather than continuing indefinitely without reassessment.