TSH improving!! but FT3 level going down - Thyroid UK

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TSH improving!! but FT3 level going down



I'm back at the GP's next week and he has agreed to refer me to an endo. I had a reduction of Levo from 75 to 50mg 3 weeks ago

I've recheck my T3 and T4 levels

3 weeks ago TSH 0.02 (0.27 - 4.2) now 0.12

FT4 was 15.4 (12-22) now 15.5

FT3 was 4.4 (3.1-6.8) now 3.8

So my FT3 has gone down as TSH has gone up

I've not test Total T4 before but it's 82.4 (59 -154)

TgAb 56.4 (00 - 115)

TPoAb 8.11 (00-34)

The doctor is going to let me read the letter before he sends it so that I can amend what he asks the endo. Please could you help me with what I should be asking from these results

Thanks in advance

5 Replies

Loubylou17 The advice you were given in your previous post still stands.

You weren't overmedicated when your GP reduced your Levo from 75mcg to 50mcg. As your TSH goes up, your FT3 will go down, your FT4 will as well but it's not showing yet.

You were given the quote from Dr Toft's book. Another one from an article he wrote for Pulse Online Magazine is

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l. Most patients will feel well in that circumstance.

But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

If you want a copy of that then email louise.roberts@thyroiduk.org.uk

You know that you need your vitamins and minerals at optimal levels for thyroid hormone to work properly and these are:

Vit D - 100-150nmol/L

B12 - very top of range, even 900-1000

Folate - at least half way through it's range

Ferritin - at least 70, best half way through it's range

So it now depends on how you feel and where your optimal level lies, so you need to discuss all these things with the endo. If you are symptomatic on your current dose of Levo then you need it increased to a level where your symptoms abate and you feel well, and you have to show the evidence to your doctor that a suppressed TSH is not an indication of over medication.

Thanks I took the extract to the doctors. He told me he doesn't have enough knowledge hence the referral. I mentioned all the vitamins and minerals required he said no harm in supplementing. He took result and extract away to consider before writing the letter.


It's premature testing 3 weeks after a dose adjustment as FT4, FT3 and TSH will still be responding to the dose adjust for up to six weeks.

There was nothing wrong with TSH at 0.02. TSH has risen and FT3 has dropped in response to the dose reduction. Some people need FT4 high in range, or even over range, to deliver reasonable FT3 and this will often suppress TSH. Read Treatment Options in thyroiduk.org.uk/tuk/about_... Email louise.roberts@thyroiduk.org.uk if you would like a copy of the Pulse article to show your GP.

Loubylou17 in reply to Clutter

Thank you I've emailed Louise Roberts

Clutter in reply to Loubylou17


I forgot to mention that thyroid antibodies are negative for autoimmune thyroiditis (Hashimoto's).

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