From the Research
Definition and Composition of Armour Thyroid
- Armour Thyroid, also known as desiccated thyroid, is a natural porcine derivative thyroid supplement that contains both thyroxine (T4) and triiodothyronine (T3) 1, 2, 3, 4.
- The LT4/LT3 ratio in desiccated thyroid extract is approximately 4:1, with the mean daily dose needed to normalize serum TSH containing around 11 mcg T3 3.
History and Use of Armour Thyroid
- Thyroid hormone replacement has been used for over a century to treat hypothyroidism, with natural thyroid preparations like desiccated thyroid being the first pharmacologic treatments available 2.
- Desiccated thyroid was widely used in the past, but its use declined with the development of levothyroxine (LT4) monotherapy, which became the standard of care 2.
- Some patients with hypothyroidism prefer desiccated thyroid extract over LT4 treatment, citing better effectiveness and improved overall well-being 5.
Potential Risks and Interactions
- There is evidence that T3 is not fully restored in LT4-treated patients, and some patients may require combination therapy with LT4 and liothyronine (LT3) or desiccated thyroid extract 2, 3.
- Desiccated thyroid extract is not formally regulated by the FDA, and its use can be associated with risks, including cardiovascular events and interactions with other medications 4.
- Patients should be cautious when using Armour Thyroid, especially in combination with other supplements like testosterone, due to the potential for synergistic effects and increased risk of cardiovascular events 4.