Thyroid UK
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Why am I having trouble introducing T3?

Hi ,

I've been on Levo for 11 years now following a thyroidectomy for papillary cancer. Over past 3 years things have gone steadily downhill . I was under a lot of stress about that time and my adrenals are clearly suffering . My gp said i could be hyper and reduced levo from 150 to 125 and then ,100. I feel permantly in fight or flight mode,anxiety and problems sleeping. I ache,feel dizzy and have been told I have hypoglycaemia . After lowering my dose of Levo I was hoping the anxiety would subside. It didn't and after another year I have finally persuaded them to let me try introducing T3 to see if it would help my energy levels and balance me better.

I felt the same for the first few days. ( I took 10 in one dose in the morning) but by about day 5 the anxiety went through the roof.

I was so frightened and exhausted I stopped after a week. My consultant hasn't really got any answers as he says its a really small dose of T3 and shouldn't make much difference.

It clearly has! I'm still suffering with feeling exhausted and vision so blurry I can hardly see here what I'm typing here.

Is it because my adrenal system is weak that I couldn't tolerate the T3 and if so what can I do to help? I'd like to try again at some stage as I suspect T4 alone is not right for me but I'll be frightened that I'll have the same reaction.

Any advice would be so appreciated I'm so relieved to have found this forum!

( my TSH on 29th Apr was 2.1 , free T4 17.2 and free T3 4.0 )

Thankyou in advance,


10 Replies

Your body just may not like levothyroxine at all. This is a helpful link although one of our Doctors, now deceased, told me that my adrenals would fix themselves when properly medicated and they appear to have done so.

The following first link - the second question refers to adjusting doses. The second link is self-explanatory:-


Yes, that's what I'm wondering - maybe my adrenals are going to continue to be weak as long as I'm on the wrong type of treatment .I'm now wondering whether I try again by gradually lowering T4 with a view to just switching over to T3 or look into obtaining some natural armour .

Its so bewildering , thank you for those links !


Amanda, you don't need to taper off Levothyroxine before switching to Liothyronine (T3) or Armour.


OK that's helpful thank you , so I could just try introducing the T3 gradually without any additional T4 . I'm just worried I'll have the anxiety attacks again but maybe if my overall dose is lower & without the T4 maybe it'll be OK next time ,such a minefield !


Amanda, 30mcg T3 is roughly equivalent to 90mcg T4 but you should try 10mcg daily for a few days just in case. You'll still have T4 in your system although it will decrease daily.


Welcome to the forum, Amanda.

Do you have the lab ref ranges (the figures in brackets after your results)? It will help members to advise and comment.

Your TSH looks to be a little high for someone on medication and indicates undermedication. TSH just above or just below 1.0 is usually comfortable although some needed it lower or suppressed.

Can you halve the T3 dose and take 5mcg 4/8 hours apart and see whether you tolerate it this way?


Yes I could try that next time I suppose , I'm just so scared of trying again though I'm desperate to feel better & come out the other side hopefully.

I've just copied & pasted this, I'm not sure if its any help. Thank you!

TSH | 2.10 | | 0.35-5.5 | mU/l

Free T4 | 17.2 | | 10-19.8 | pmol/l

Free T3 | 4.0 | | 3.5-6.5 | pmol/l


Amanda, your FT3 is low in range so T3 should help you if you can tolerate it.


Have you had your ferritin and serum iron checked? These need to be high in range and Ferritin should be 70 plus. Also check B12, Folate and Vit D. Being low in any of these will give you symptoms and for myself it was being anaemic that made it impossible to tolerate T3 or NDT. I have had TT also and wonder if we find it difficult to absorb iron from food. I now take a supplement every day and can take NDT and T3 without any problem. Your GP should be willing to test all of these. By the way with TSH at that level you are not hyper and probably never were. Did your GP check your levels before reducing your dose?


Thank you ,I will certainly try to get my g.p to test those levels.

He did test levels before he reduced my dose and wanted to keep it at 150 to over replace and surpress any remaining thyroid tissue. It was me who asked to be lower in the hope it would ease the anxiety and sleep problems. Unfortunately it has made no difference.

Can I ask if your gp prescribed the natural form or did you have to go elsewhere?

Also, what is the reason for taking T3 too , does the natural form not contain T3and T4?

Thanks again,



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