Thyroid UK

Does everyone eventually feel better on T3 only

Hi, 6 weeks ago I decided to try T3 only after still feeling tired on T4/T3 combo.

I was taking 18.75 T4 and 17.5 T3 and didn't feel great, but when I started T3 only I

increased it slowly and am now taking 22.5mcg @ 5.30am another 5 @ 11.30 and

5 @ 4.30. At first I felt a little better, my brain fog cleared and my pain was a little better,

but now I'm so tired and have terrible sweats, I also feel sometimes as though I'm out

of breathe. I sing in a choir and found myself breathless and felt like I was going to pass


Has anyone else had this happen to them, I don't know whether to give up or carry on.

I am on the Recovering T3 FB, but wanted others opinion too.

Thank you.

17 Replies

There is no guarantee that everyone will feel well on T3. Some people have to have T4 in the mix too.

But your dose is really quite small. A total of 32.5mcg per day would not be enough for many people. It's probably equivalent to about 100mcg T4 or possibly even less.

Another issue of course, is what brand of T3 are you taking? I know that UK T3 has a reputation for being weak and unreliable in strength. Perhaps you have been given a dodgy batch.


Hi humanbean,

Thank you for replying, I'm taking the Thybonn Henning T3 from Germany, the Cytomel is too expensive.

Perhaps I should just increase it and see what happens, but it's a bit of a worry as I know we have to be careful not to have too much, but I can't carry on like this, I'm exhausted and look ill.

I don't know how long I should keep trying for, before I go back to T4/T3.

My GP told me to only take 75mcg T4, he says that's all I need, no wonder I was really poorly on just that.

Thanks again.


Do you monitor your temperature, your heart rate and your blood pressure? They can give helpful clues about what is going on. If your temperature before you get out of bed in the morning has risen above normal, then you have over-done the T3. A fast pulse and/or high BP can indicate a possible over-dose as well.

You might find this helpful :


Yes I do, my pulse is actually only mid to late 60's before I get up, my temperature has got better it can be 36.5, but today it was 36.2. My pressure is better as well, it was 104/56 this morning, so that's ok.

Thanks for the link.


On the basis of those numbers, if they were mine, I would assume I was unlikely to be over-dosed, and therefore I had room for manoeuvre in raising it.

Hope it works for you, and you find your "sweet spot". :)

1 like

Thank you, I think I will try and up it a little and see what happens.

Thanks again. :-)


TJM3, I suggest you have a FT3 test to check you aren't overmedicated. 32.5mcg is equivalent to 97.5mcg T4.


Ok Clutter, that's a good idea, thank you.


if you are like my husband or daughter and highly sensitive to chemicals of all kinds then synthetic T4 and T3 often does not suit them

Yet on NDT they are fine


I've tried the NDT and that really didn't suit me, I've tried

it twice, but have no luck with it, but thank you anyway.


I would hazard a guess that your body cannot convert the T4 in NDT into the T3 your body needs maybe due to D I02 Gene


Oh right, I've heard about the D 102 Gene, that would explain the Thyroxine T4 conversion to T3 as well then because I don't convert well to T3.

I don't have any in date NDT, sorry, but thank you for the thought.


How out of date is your NDT?


16 months and there's only 10 left, I should have thrown them away, I forgot about them.


Do you still have in date NDT because my daughter would happily swop it for T3


TJM3 - it took a year before I felt any benefit of taking T3. The longer you've been ill the longer it will take to recover.

Make sure vitamins and minerals are good, for me the breathlessness was attributed to low zinc. My lungs will now open completely.


Oh right, that was a long time to feel any benefit, I have been ill for years so I suppose it will take a while then.

I have a feeling that my zinc is low, I was only talking about it last night, saying I think I should get it checked.

I'm glad you're feeling better and thank you for your comment.


You may also like...