Why is my TSH level not rising despite a significant decrease in T4 medication?

I have been suffering with Hashimotos for several years and have been lucky enough to see a forward thinking endocrinologist who has agreed to give me a trial of T3. When I first went to see him I was on 125mg of T4 and very symptomatic. He did lots of tests for other autoimmune diseases which all came back negative. He agreed to allow me a trial of T3 if my TSH level rose when my T4 was decreased. So I went down to 100mg and 3 months later my weight plummeted and my TSH was still suppressed. I was devastated. He could see how upset I was and agreed to let me trial T3 along with another reduction of T4 (now on 75mg along with 25 T3). Just had blood tests done after 2 months and my results are as follows:

TSH 0.06 - subnormal, free T4 10.7 (9.0 - 19.1), free T3 3.97 (3.6 - 6.5)

I feel awful and am still putting on weight which is making me feel even worse.

Any help here would be much appreciated. I have got to have another blood test done before I go back to see him in July, but I can not see it improving any. :-(

9 Replies

  • When you take T3 or NDT its very common for TSH to be undetectable

    Its simply the correct action of the pituarity feedback system

  • Yes that is what my endo has suggested. He also stated that he is concerned about my persistently subnormal TSH. Given my profound symptoms he has not made any adjustments to my medication at the moment as reducing my T4 will only make me worse, but wants me to have another blood test before I return to see him. What is worrying me is that he is going to reduce my T4 or stop my trial of T3 all because of my TSH level. Any ideas?

  • Feelold, do make sure that you don't take thyroid meds before your blood test as this will skew the results, making your TSH appear lower than it usually is.

    Did you feel any improvement in your symptoms when T3 was added? Your FT3 is very low and IMO an increase in T3 with a decrease in T4 will be beneficial.

  • Yes I always make sure I take my meds after my blood test and also that my appointment in first thing in the morning. During the first couple of weeks I did feel an improvement in my symptoms, however after that they returned as bad as before and my concentration has become worse :-(

  • Feelold, initial improvement then a plateau or drop back can be a sign that more T3 is needed. It's worth discussing with your endo.

  • Thanks Clutter I will be doing just that.

  • Its quite possible you have Central/2ndary Hypothyroid which is pituarity /hypothalmus problem and not as rare as they like to pretend

    both my husband and daughter have it along with Hashimotos

  • Oh I am sorry to hear that your husband and daughter have this. How was it diagnosed?

  • They have to do a special blood challenge test cant remember thename

    But both are well on NDT but cannot tolerate either levthyroxine or T3

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