Desiccated thyroid is a hormone supplement made from dried, powdered thyroid glands. Desiccated thyroid is usually obtained from the thyroid glands of pigs or cows and specially formulated for therapeutic use. Sometimes referred to as thyroid extract or natural thyroid, these supplements are generally used to treat the underactive thyroid condition known as hypothyroidism. Desiccated thyroid may also be used to treat other thyroid conditions such as goiter and Hashimoto’s disease, an autoimmune disorder.
Desiccated thyroid works by replacing the hormones T3 and T4, which are naturally produced by the thyroid gland to regulate body metabolism. This includes the conversion of nutrition to energy and regulation of body temperature and heart rate. When thyroid hormone levels in the bloodstream drop below normal, the pituitary gland produces thyroid stimulating hormone (TSH), which sends a message to the thyroid gland to produce more T3 and T4. When the thyroid cannot produce enough of these hormones, supplements must be taken to maintain a healthy metabolism. A test that measures thyroid hormones in the bloodstream is used to determine whether thyroid supplements are needed.
Desiccated thyroid is made by drying the thyroid glands of pigs and cows, which are then ground into a powder, mixed with binding agents, and compressed into pills. These pills contain a thyroid hormone ratio of approximately 80 percent T4, and 20 percent T3. They are available in a range of strengths from one-eighth grain to five grain tablets. Armor and Company, one of the largest meat product manufacturers in the United States, is also the leading brand of desiccated thyroid supplements.
Desiccated thyroid has been prescribed by doctors in the United States and Great Britain since 1891. In the 1960s, pharmaceutical companies began producing levothyroxine, synthetic thyroid supplements, which rapidly gained preference over desiccated thyroid. There has since been an ongoing debate over whether synthetic thyroid is safer and more effective than desiccated thyroid. Today, the majority of doctors prescribe synthetic thyroid supplements because of their precise formulation. Some doctors still recommend desiccated thyroid, especially practitioners of alternative medicine.
Thyroid supplements are powerful physiological agents and should not be used without the supervision of a qualified health practitioner. Synthetic thyroid hormones require a prescription; desiccated thyroid may be purchased over the counter. There are recent indications, however, that the Food and Drug Administration (FDA) may ban desiccated thyroid supplements in the U.S. Desiccated thyroid is not recommended for vegans, vegetarians, and individuals whose religion prohibits the consumption of pork.