Thyroid UK
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LOw T4

Hi, I have Hasmimotos, positive for the Di02 gene. I cannot tolerate levothyroxine. I am prescribed Liothyronine by my Doctor. My most recent blood tests produced the results: TSH 1.28. (ref 0.25-5.5) T3 1.8(0.9-2.8) T4 3.7. (9-24)

I am feeling like I am running on empty. Is the t4 level low considering that I am on t3 only? I don't have an obvious problem with gluten but I understand that hashimotos people benefit from being gluten free. I also have Horners syndrome with no obvious cause.


2 Replies


As your thyroid gland isn't producing T4 and niether are you supplementing, your T4 will be low.

However, there's no need to worry. I am on T3 only as well.

Levothyroxine is no good to anyone as it is the inactive hormone and it's job is to convert to T3. So taking T3 only you would expect a higher T3 and low T4.

The main thing is 'how are you feeling'. If not 100% you need an increae in T3.

The blood tests used by the doctors were introduced along with levothyroxine. So cannot correspond to those of us on T3 only or on NDT.

This may be helpful as this doctor never prescribed levothyroxine, only NDT or T3 only.

I am now well on sufficient T3 for me but I didn't particularly like UK T3 or, should I say, it didn't suit me so well.

I hope you get to a dose which suits you, particularly as you have the DI02 gene defect and you can only take T3.



FT4 will be low because you are taking T3 and therefore don't require T4 for conversion to T3. I think it may be helpful to increase dose so that FT3 is closer to top of range and TSH below 1.0.


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.


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