I don't think this general statement is true. A lot of people need Levo over 3, and going on a low dose helps. Of course it's not the entire story and everything else should be tested, but if I'm above 3.5ish on TSH, there's a pretty good chance I'm not feeling my best and will talk to my doctor about a dose increase. Similarly, if I'm under 1, there's also a good chance I'm feeling unwell and will talk about a dose decrease. TSH isn't the whole story, but it is helpful, especially in those who have been testing for a long time and know where they feel comfortable.
The problem I’m pointing out here is the lousy TSH which is a flawed test without the thyroid hormones being tested. One can have a TSH of 1 and have hypothyroidism if their Free T4 is below mid range and the Free T3 is below mid range or not in the upper top quarter. A lot can be missed when only testing the TSH and basing medication dosing on the TSH. That’s laziness by mainstream medicine contributes to metabolic syndrome. Test your Free T3.
The TSH isn’t a thyroid hormone nor does it contribute to how one feels. The T3 is the action/ active hormone.
A person not on any thyroid treatment who has suppressed TSH could easily be hyperthyroid (unless they have a pituitary issue). But this situation is totally different and it has been applied to thyroid patients under treatment and used to keep many under-medicated.
Being thyroid less is just at one end of the spectrum of thyroid patients. Many thyroid patients who are on thyroid hormone treatment have some loss of thyroid hormones from their thyroid gland. These people may also need very low TSH in order to get well.
This means that on thyroid treatment, TSH could be anywhere from just inside the top of the lab range right down to near zero. Thyroid treatment might even need to be increased when TSH is suppressed in order to get a therapeutic response i.e. to eradicate a thyroid patient’s symptoms. This does not mean that the patient is hyperthyroid. It simply acknowledges that the person needs more T3 converted from T4 to feel well, i.e. enough of the actual active thyroid hormone.
Ok, so where does that leave us in terms of knowing if a thyroid patient is properly treated?
The answer is “Nowhere” if TSH is the only measure!
TSH tells us very little other than the patient’s pituitary gland is responding correctly as the thyroid medication is increased. Being low in the range on TSH does not mean the patient is correctly treated with the right amount of thyroid medication or even the right type of thyroid medication!
The use of TSH to determine correct treatment level is flawed!
Doctors and endocrinologists are ultimately going to have to face up to the science and begin to ignore their sacred TSH. It is not the beacon of light onto the correct treatment level at all.
The logic of using TSH comes crashing down!
