Thyroid extract (also called Armour thyroid or Natural thyroid) can be more effective treatment than conventional thyroid medication - because it contains T3. NOT because it is bioidentical or natural.
Thyroid extract is desiccated thyroid gland from a pig. It has a long history of use in medicine, and 50 years ago, it was standard prescription. Thyroid extract contains both T4 and T3, and therein lies its advantage. Many people feel better when they add an activated version of thyroid hormone (T3).
Standard T4 (thyroxine) IS bioidentical. But it's not T3. The T4 in thyroid extract is EXACTLY the same hormone as the T4 in conventional thyroxine. Therefore, thyroid extract is not any more bioidentical than conventional T4.
As far as medications go, conventional thyroxine is not the worst thing. It is the same T4 hormone that our thyroid makes. But T4 is a prohormone. It needs to be activated into T3, and very often that activation doesn't happen. (Due to things that suppress deiodinase activity such as insulin and leptin resistance, low-calorie dieting and chronic inflammation). (See Lara's deiodinase article).
When T4 alone is NOT enough, then taking the activated version of thyroid hormone (T3) can be very helpful. It can be taken thyroid extract OR as conventional or slow-release T3 prescription. (For more information, read Lara's full thyroid article.)
The term bioidentical became important as applied to complex steroid hormones such as natural progesterone. In standard medical practice, a harmful synthetic version of progesterone (progestin) was used for many years and caused a lot of problems. We now know that it was the synthetic progesterone (progestin) that was the main cause of the breast cancer and heart disease risk in the 2002 Women's Health Initiative HRT study. Natural progesterone is different at a molecular level than synthetic progesterone (progestin). Natural, bioidentical progesterone is vastly preferable to synthetic versions of progesterone. That same distinction does NOT apply to thyroid hormone.
Furthermore, to truly treat thyroid disease, the underlying autoimmune problem must also be addressed.
(For more information, read Lara's full thyroid article.)
Article by Lara Briden