Opinions on FT3 result please

I posted a question recently about having diarrhoea in the morning and got some really useful answers. In the end I decided it must be related to the levothyroxine dosage so reduced it from 100 mcg to 75 mcg and that seems to have helped a bit. After a week on 75 mcg I did a private blood test and the results are:

TSH 0.33 (0.27 - 4.2)

FT4 21.0 (12.0 - 22.0)

FT3 4.1 (31. - 6.8)

I wanted my TSH to be low but probably that's too low. In May 2013 it was 2.85 (0.25 - 4.0) and FT4 was 20 (12.0 - 22.0). No FT3 because that was NHS.

Previous private FT3 results are July 2010 4.0 (3.0 - 6.2) and Oct. 2012 4.2 (3.1 - 6.8).

Is my current FT3 of 4.1 significant in the light of the TSH and FT4?

7 Replies

  • Hi - I think that those blood tests won't be very accurate, as you have had them taken after only 1 week on the reduced dose. I think blood tests take 4-6 weeks to settle after a dosage change. That said, I think that your fT3 looks rather low - I need mine to be over 5 to feel well. Is there any chance you could add in some T3? xx

  • Yes, I see what you're saying about the accuracy of the tests. I had originally intended to do the test the day before I reduced the dose, to see if the dose might be too high, but there was a delay in sending the test kit.

    I'm grateful for the comment about the T3 as I was wondering if it was too low. I'm due to see my GP on Monday so will take the results and ask about T3.

  • Your free T4 is high... are you taking levo AND T3? You may have a conversion issue

    Have you taken the adrenal questionnaire? if you have high score here the T4 may make you feel worse not better.. have a look


    Let us know what you get

  • Yes I agree about a possible conversion problem with a high fT4 and a low fT3. My endo agreed to some T3 when I pointed out to him that the 50mcg of thyroxine he prescribed me, caused my fT4 to go up, but my fT3 to drop. I am now on Armour, which contains T3, and feel a million times better than on T4 only. Good luck with your doctor. xx

  • me too.. armour is great....I feel like myself again after a long time

  • No, I'm just taking levo which is why I was wondering about the T3. I've had a look at the adrenal fatigue questionnaire and I don't think that's the problem but thanks for the suggestion

    Will let you know what GP says..

  • Saw GP yesterday and he thinks FT3 is OK. I will keep an eye on it - he was quite happy to accept Blue Horixon test. However it was obvious from what he said that he does know about adding T3 and I think would do it if he thought it necessary. For the moment, he agrees perhaps my dosage went too high too quickly (various factors - the fact I should have been treated years ago (different GP), hot weather coinciding with the increase to 100 mcg, my age (66)) so has reduced it to 75 mcg for 3 months, which I'm happy with. I'm prepared to try that and see what happens.

You may also like...