Is Letrozole safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Letrozole. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
Relevant published information was not found as of the revision date.
Effects on milk supply
Relevant published information was not found as of the revision date.
Levels in milk
Maternal Levels. An abstract reported that a relative infant dose of 10.2% was found in nursing mother(s) taking letrozole, who provided 8 milk samples over 24 hours, but other details were not supplied.[ 1 ] Infant Levels. Relevant published information was not found as of the revision date.
“No published information” means the studies do not exist yet — not that Letrozole is known to be harmful, and not that it is known to be safe. Your prescriber or pharmacist can weigh your baby's age and whether a better-studied alternative would do the same job. Worth asking before stopping a medicine you need.
Source: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.