Discussions that mention synthroid

Thyroid Disorders board

Hi everyone

I just got new lab results after being on synthroid 0.025.

My tsh is down from 3.9 to 1.06 normal range 0.35-5.00
which is great.

My ft4 is down from 15 to 12 normal range 10-20.

Why is it after taking t4 that my numbers have actually decreased?

I have read that the t4 should be on the high end of normal. If my dose was increased to bring t4 to the high end, wouldn't my tsh go to low?

My doctor, who is great to talk to and very easy to look at (ha ha) has kept me at the same low dose for another month to see if there is any further improvememnt.

Any input on this would be greatly appreciated.

I am certainly not the best person to answer your question, but I will offer some comment...

There is some opinion that taking a very low dose (yours is 25mcg, if I read that right) of straight T4 (such as levoxyl, synthroid, etc.) actually does more to supress the thyroid. The low does is just enough to make the pituitary think that the thyroid is producing. Thus the pitutary secretes less TSH, which in turn, tells the thyroid to secrete less T4 and T3, etc. But the T4 dose you are taking is so small, that it does little to make up for this factor.

Don't know if there is any validity to that thinking.

I have progressivly backed off my dose to 50mcg, and I feel better on that right now (better, not great though). I'll be testing my FT3 and FT4 in 10 days. I almost do expect to see low numbers, since I still have Hypo symptoms. But I don't have previous numbers to compare.

Let's see who else repies - I'm a newby.