To know how a thyroid glandular supplement works, you need to understand about the two thyroid hormones, T3 and T4.
T4 is the predominant hormone produced by the thyroid. It contains the amino acid tyrosine with 4 molecules of iodine attached. T4 is weakly active and is converted to the highly active T3.
T3 looks like T4 except that it has 3 molecules of iodine attached to tyrosine.
The conversion of T4 to T3 is dependent upon the enzyme selenomethionase, which uses the mineral selenium. Since many people are deficient in selenium, the conversion is frequently a problem. The best dietary source of selenium is Brazil nuts. (link)
There are smoothie recipes with nutrients for the thyroid including Brazil nuts (here).
Prescribed Thyroid Medications
The most common prescribed thyroid hormone replacement is a synthetic form of T4 called Levothyroxine (Synthroid). Some people get good results from this. However, many people do not. A common reason that many doctors shy away from Levothyroxine is that the body still has to convert T4 to T3 and since many patients are deficient in selenium, this conversion does not go well.
I know many traditional doctors who prescribe Levothyroxine, however most functional medicine doctors do not recommend it. A functional medicine doctor is typically going to spend a lot more time looking for the cause of the problem rather than giving a quick recommendation.
So what do functional medicine doctors recommend?
If a prescription is given for the thyroid, it is usually Thyroid Dessicated (Armour, Nature-throid, Westhroid). This contains both T4 and T3. Also, the doctor usually recommends supplements to go along with the prescription, including a daily dose of 400 mcg of selenium.
If a prescription is not given, the recommendation is usually a group of supplements that feed the thyroid and help with conversion such as selenium, magnesium, L-tyroisine, and iodine. (click here)
Thyroid glandular does not contain active T4 or T3, but contains the RNA of the gland that is useful to support and heal the thyroid gland. (I use a few different brands for this).
If you would like your blood work analyzed for thyroid function (click here).