Thyroid UK
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Thyroid blood tests over the years

Hi all

I wonder if I could get some opinions from the community here? I've just received a print out of all my regular bloods over the last 8 years since HT diagnosis. What is really interesting is that in recent years, despite my dose not changing - that is to say Levo 150mcg and Lio 60mcg for the last five years or so, my T4 bloods have steadily fallen and are now just 12. My TSH has been consistently suppressed since starting on Lio (no surprises there).

At diagnosis, my TSH was 13.5

I was prescribed increasing doses of Levo over the following 18 months until I was taking 250mcg Levo. The bloods at that time were TSH 0.014 and T417.7 However, because I was still really unwell despite a suppressed TSH, Lio was added to my daily meds.

I reduced my Levo dose back to 150mcg and Lio 60mcg which I have remained on to this day. Wellness has been restored, my TSH has remained suppressed at 0.014 and my T4 has steadily continued to fall away to just 12 (just above bottom of the range), at the last blood test a few weeks ago.

Can anyone shed any light on what may be happening? I'm now 52, probably menopausal, not that I'd notice. My GP is in a flap about it and wants me to see an endo. I'm not keen, but would like to have some idea from you clever lot as to what might be going on and how I can remain in control of this situation when confronted by the doctors about it.

Thanks very much in anticipation

5 Replies

Well, it all seems pretty normal, to me. When you're taking that much T3, your TSH is bound to be suppressed because you no-longer need it. The pituitary has sensed all that T3 in the blood and is therefore no-longer secreting TSH to stimulate the thyroid gland. And, as that's just about all the TSH does, then it's surplus to requirements.

The FT4 is also going to be low, because you do not need it. T4 is a storage hormone that is converted into T3 as needed. But, you're taking your T3 ready-made, so to speak, so the body doesn't need to hang on to as much - just a little bit, in case of emergencies. In fact, most of that T4 you're taking, is being excreted.

If you feel well, that is the main thing, and no real need to change. Although you could, if you wished, try reducing that T4 a little, I doubt you need it. It's just making expensive urine. But, do this on your own, don't involve your doctor. If a doctor reduces your T4 then you will have trouble getting it increased again, should it turn out you need it!

You are not obliged to see an endo - I certainly wouldn't recommend it, if you feel well, because in actual fact, they know very little about thyroid. Just tell your doctor you are happy with the way things are, and you'd prefer to leave it at that. :)


Thank you greygoose. Very sensible advise. I do still wonder why my T4 is falling and thought maybe the body was converting it to RT3 because I am taking too much.

In the meantime, because of the threat hanging over the supply of Lio and so that I can stock pile if necessary - I have reduced my dose of Lio to 40mcg. I feel okay actually, almost a week in.

I think its a good idea to reduce my dose of Levo as well - see what happens. I'll give it a month on reduced Lio then, if all is good, will reduce levo too. :)

Regarding the endo - I wont be bullied into going.

Also, am I right in thinking that I can insist that my prescription remain unchanged?


No, sorry, you can't insist on anything. The doctor always has the whip-hand. He can do what he likes. But, it's always good to make your disagreement felt. He who says nothing, agrees.


I find it really scary just how little control we have over our lives and our bodies, in so many respects. At the stroke of a pen, my quality of life and ability to remain a fully functioning, productive and happy member of society could be taken from me.... Unless that is, I have deep pockets or the guts to self-medicate :(

1 like

You're a 1st Dan. You have plenty of guts :-)


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