Many women wonder if they should continue taking prescribed thyroid hormone replacement drugs, such as Synthroid, Levoxyl, Levothroid, Armour, Thyrolar, or generic levothyroxine, when breastfeeding. Some women worry, in particular, because nursing mothers are told not to take any medications while breastfeeding.
Thyroid hormone replacement, when taken at the prescribed dosage level to maintain the mother's thyroid at a normal level, crosses into breast milk in only minute quantities, and has no adverse effect on the baby.
Taking too much thyroid hormone medication, however, can cause hyperthyroidism in the breastfeeding mother, and some excess thyroid hormone can pass into the breast milk and to the baby. A nursing mother on thyroid hormone should, therefore, take medication exactly as prescribed by a physician, and have periodic retesting in the postpartum period to ensure that any fluctuations in thyroid function don't result in overdosage.
Read more Frequently Asked Questions About Breastfeeding and Thyroid Disease
