On T3 and T4 has dropped and TSH rose?

I'm a euthyroid Hashi's person. I was trailed on 25mcg of thyroxine that saw no real change in my results - tsh was 1.79 and then 2.11 and FT4 was 9.6 and then 11.2 and my symptoms of anxiety and depression remained the same.

I was changed to 10mcg of T3 (liothyronine) also on a trial basis. Been on it for about 3 weeks now. Have been feeling more anxious if anything. The GP tested my TSH which is now up at 2.76 and FT4 which has dropped to 8.4. Of course getting FT3 tested is like getting blood out of a stone.

I will contact my endo about these results. Has anyone else experienced a rise in TSH and drop in FT4 when on Liithyronine?

19 Replies

  • You say you felt no better when 25mcg of levo was prescribed. I'm not surprised as this is such a low dose. I know, I was prescribed 25mcg when I began and now I am much more 'experienced' realise that 25mcg levo (unless very frail with a heart disease) is only really for an incremental dose when the starting dose was 50mcg.

    Again, unless you have a heart complaint 10mcg of T3 is equal to around 30mcg of levo.

    You need another doctor or someone who knows how to treat patients (mind you that seems to require some detective work these days.

  • If you email louise.warvill@thyroiduk.org.uk and ask for a copy of Dr Toft's Pulse online article. Go down to the para in which he states about treating antibodies (I know some Endos wont prescribe for antibodies) - excerpt:

    But if it persists then antibodies to thyroid peroxidase should be measured. If these are positive – indicative of underlying autoimmune thyroid disease – the patient should be considered to have the mildest form of hypothyroidism.

    In the absence of symptoms some would simply recommend annual thyroid function tests until serum TSH is over 10mU/l or symptoms such as tiredness and weight gain develop. But a more pragmatic approach is to recognise that the thyroid failure is likely to become worse and try to nip things in the bud rather than risk loss to follow-up.

    Treatment should be started with levothyroxine in a dose sufficient to restore serum TSH to the lower part of its reference range. Levothyroxine in a dose of 75-100µg daily will usually be enough.

  • Halinka, FT4 drops when patients are taking Liothyronine (T3) only. TSH has risen because 10mcg T3 is an insufficient dose and needs increasing.


    I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

  • It'll be interesting to see what he says. I'll let you know.

  • Are there risks with FT4 dropping? I know he won't be worried about my TSH as it's not at 5 > That said, the tendency is upwards so that should tell him something. I had bloods done before taking my T3. Am I right in thinking that my TSH would have been even higher, had I taken the T3?

  • Halinka, no risks with low FT4. T4 is a storage hormone which converts to T3, the active hormone. Taking oral T3 means you don't need T4 for conversion but you do need sufficient T3 else TSH rises. TSH should drop after taking T3 but it's not an instant reaction and takes time to respond to circulating hormone in the blood.

  • Thank you Clutter. How long does it take to respond? I've been on the t3 for about 18 days now.

  • Halinka, that's long enough if you were on sufficient dose. I don't think you are.

  • Thanks Clutter. Can I ask, was I right to not take my t3 before bloods? If I had, would my TSH have been even higher? Thanks

  • Halinka, You're right not to take thyroid meds before a blood draw. I don't think TSH would have been higher if you had but FT3 would.

  • This happened to me when I trialled T3. I was advised to increase the dose but this did nothing for me - my TSH continued to rise. In fact, it seems that synthetic T3 did not suit me at all. I don't have the same issues with NDT, which also contains T3.

  • What dose did you go up to of T3?

    Are you in the UK? I get the impression from the Endo that prescribing NDT is not the done thing here.

  • I started on 5mcg and gradually raised to 20mcg. I am in the UK. NDT can be obtained on private prescription from some doctors.

  • Thanks for that info. I will email the endo.

  • Hi the same has happened to me. MY t4 has been in the middle to high of the range but starting on t3 my t4 is now below range and my tsh has risen quite a lot too.Feels like the doctors dont take hashimotos seriously

  • No they don't

  • So how long should it actually take to feel/see a difference when adding T3 to the T4? I started on T3 9 days ago. I am currently taking .137 Synthroid and 5mcg of T3 twice daily. I feel some what better, however, not experiencing the 'feel better' I thought I would. Have much more stamina since having my Synthorid upped in July to the .137. I can really tell that difference. Endo won't retest me until March! So if I read correctly from previous replies my TSH will rise? When I had it tested this last time it was at .525 and my T3 was at the bottom of the range. Just curious how this all works. Since if I am correct am taking the equivalent to .167 Synthroid?

  • This is just my experience. It's anecdotal as are the other posters' experiences. I come on here to hear about others experiences but then I go back to my endo to get confirmation of why something might be happening.

  • Thanks

You may also like...