Dear Lactnetters, I have received no confirmation based on pharmacologic or research evidence that ibuprofen interferes with milk let-down. I received one e-mail regarding delayed let-down during mastitis while taking ibuprofen. In the one case with which I am personally acquainted and in the four other cases about which I now have second-hand information, it appears to me that the pain (and/or other factors) rather than the ibuprofen may have been at fault. I have no reason to believe at this time that women should be advised against use of ibuprofen during breastfeeding because of concerns over its alleged interference with the milk ejection reflex (let-down). There does not appear to be any hard evidence that supports this observation. Bonnie Jones, RN, ICCE, IBCLC