TSH Do we need it?

[Wolverine]

For many taking thyroid meds like Armour, their TSH is suppressed. Is this a bad thiing? My FT3 and FT4 levels are at good levels on Armour. My TSH is suppressed at .009 (.45-4.5). I feel good but am wondering about negative effects (if any) of a suppressed TSH. Thanks for any and all input.

 

[HarryCat]

My $.02, I agree with this assessment from here: http://tiredthyroid.com/tsh.html

"If the primary role of TSH is to aid in T4 to T3 conversion at the cellular level, then someone with low TSH may have insufficient T3 levels. In fact, many patients initially report a low TSH with low T3 levels, but T4 levels close to mid-range. On desiccated thyroid, a suppressed TSH is a common side effect, because the T3 content in desiccated suppresses stimulation from both the hypothalamus and pituitary. So anyone taking desiccated thyroid may have limited T4 to T3 conversion due to a lack of TSH. But desiccated thyroid contains T3, so the loss of conversion is compensated for by the same T3 that is suppressing the TSH. In any case, it is possible to live with a suppressed TSH, and many on desiccated thyroid do just that, because they find that keeping their TSH in range means they’ll still have hypothyroid symptoms. "

So if you feel good, don't mess with what you are doing.

 

[Neil Olson]

My TSH stays around .01 because of my pituitary issues. I only require T4 meds though. T4-T3 conversion is going well.

 

[Vettester Chris]

You can essentially look at TSH to the thyroid as you would LH to the testes and testosterone. Both are secreted in the pituitary and designed to prompt, or call it signal the production of their respective hormones via the negative loop feedback. This is a great setup "when" it works! However, for a myriad of reasons most of us know that sometimes it just doesn't work as it should.

The pituitary can stop producing a "normal" amount of LH, thus secondary hypogonadism sets in. Introduce exogenous testosterone, your serum levels increase, which will cause LH to pretty much stop all together.

Same is true with TSH < ------------> Thryoid -> T4, T3, T2, T1 ... Add an exogenous source (could be Synthroid, Cytomel, NDT, ...), the pituitary will register that as "thyroid hormone levels increased", this in turn prompts the pituitary to reduce TSH "stimulation hormone".