Alternative medicineBy Mayo Clinic staff
Most doctors recommend levothyroxine, the synthetic form of thyroxine (T-4). However, natural extracts are available that contain thyroid hormone derived from the thyroid glands of pigs. These products — Armour Thyroid, for example — contain both levothyroxine and triiodothyronine (T-3).
Doctors have a number of concerns about natural thyroid hormone extracts such as Armour Thyroid, including:
- The balance of T-4 and T-3 in animals isn't the same as in humans.
- The exact amount of T-4 and T-3 in each batch of a natural extract product can vary, leading to unpredictable levels of these hormones in your blood.
Still, researchers have investigated whether adjusting standard hypothyroidism treatment to replace some T-4 with T-3 may offer benefit. The majority of studies have determined that the addition of T-3 does not offer any advantage over treatment with T-4 alone.
However, there is some evidence that T-3 may offer benefit to certain subsets of people, such as people who have had their thyroid surgically removed (thyroidectomy). Research is ongoing.
- Davies, TF. Pathogenesis of Hashimoto's thyroiditis (chronic autoimmune thyroiditis). http://www.uptodate.com/home/index.html. Accessed Nov. 15, 2010.
- Frequently asked questions: Hashimoto's disease. US Department of Health & Human Services. http://www.4woman.gov/faq/hashimoto-thyroiditis.cfm. Accessed Nov. 15, 2010.
- Hashimoto's thyroiditis: Information for patients. American Association of Clinical Endocrinologists. www.aace.com/pub/thyroidbrochures/pdfs/Hashimoto.pdf. Accessed Nov. 15, 2010.
- Hashimoto's thyroiditis. American Association for Clinical Chemistry. http://www.labtestsonline.org/understanding/conditions/hashimoto-4.html. Accessed Nov. 15, 2010.
- Hashimoto's thyroiditis. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/sec12/ch152/ch152d.html. Accessed Nov. 16, 2010.
- Ross DS. Treatment of hypothyroidism. http://www.uptodate.com/home/index.html. Accessed Nov. 16, 2010.
- Hashimoto's disease. The Hormone Foundation. http://www.hormone.org/Resources/Thyroid/loader.cfm?csModule=security/getfile&pageid=1113. Accessed Nov. 17, 2010.