Skip to main content

Thyroid desiccated Pregnancy and Breastfeeding Warnings

Medically reviewed by Last updated on May 2, 2023.

Thyroid desiccated is also known as: Armour Thyroid, Bio-Throid, NP Thyroid, Nature-Throid, Thyroid Porcine, WP Thyroid, Westhroid

Thyroid desiccated Pregnancy Warnings

Animal studies have not been reported. Thyroid hormones do not readily cross the placenta. Clinical experience to date does not indicate any adverse effects on the fetus when thyroid hormones are administered to pregnant women. There are no controlled data in human pregnancy.

US FDA pregnancy category A: Adequate and well-controlled studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).

Use is considered acceptable.

US FDA pregnancy category: A

See references

Thyroid desiccated Breastfeeding Warnings

Caution is recommended.

Excreted into human milk: Yes

-Liothyronine (T3) and levothyroxine (T4) are normal components of human milk; if replacement doses are required by the mother, it is not necessarily a reason to discontinue breastfeeding.
-Dose requirements may be increased in the postpartum period compared to pre-pregnancy requirements in women with Hashimoto's thyroiditis.

See references

References for pregnancy information

  1. "Product Information. Armour Thyroid (thyroid desiccated)." Forest Pharmaceuticals (2022):

References for breastfeeding information

  1. "Product Information. Armour Thyroid (thyroid desiccated)." Forest Pharmaceuticals (2022):
  2. United States National Library of Medicine "Toxnet. Toxicology Data Network." (2013):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.