Optimal Thyroid Function:  The How's and Why's

• Free T3 and Free T4 should be measured.  I do not use TSH as the way to follow thyroid function.  I think TSH is best used to monitor pituitary function.  In the past, TSH was the best way to measure the need for thyroid and to follow the amount of medication given, but I think that new evidence and better ways of measurement now suggest otherwise.  For evidence read this article about the measurement of thyroid function and this article about the effects of replacement of both T3 and T4.
• Thyroid should be optimized by adjusting to the upper 20% of normal in the person with fatigue, obesity, depression, or risk of dementia.  This article documenting that women in the lower 20% of NORMAL have about twice as much risk of dementia as do women in the upper 20% of normal gives evidence for this strategy.  The real test of a physician is this:  "Do his patients get well?"  Most of my patients (with obesity, depression, fatigue, and difficulty concentrating) get well when thyroid is adjusted this way (in conjunction with other strategies).
• Armour thyroid works better than Synthroid for most people.   With over 280 hormones made by the pituitary gland alone, I think it's prideful for physician's to think that we know all that the thyroid does and every chemical that it produces.  Armour thyroid is a natural product made from pig thyroid gland.  Not only does Armour supply the T3 that's know to be missing from Synthroid, Armour thyroid may have other hormones in it which you may not receive in Synthroid.  After swapping over two thousand people from Synthroid to Armour thyroid, I've had less than 10 want to go back to Synthroid.  I cannot prove what I don't know about.  So, I admit that postulating that we don't know everything about the thyroid yet is not the most scientific statement, but the test is this:  "Do you feel as well as you would like to feel while taking Synthroid?"  If you do, then don't change.  If you don't, consider that maybe you need something else.  Here's a link to the Armour Thyroid site if you want to know more about this product.