Thyroid UK

Can't tolerate Thyroxine?

Will keep this short. New post. Previous stuff on this site if you've the time and inclination to read it!

Anyone out there who can't tolerate Thyroxine? After my first good week for over a year now that I'm on a combi of 75 mcg Thyroxine and 15 mcg T3, I've crashed again today to all the usual stuff - migraine, joint pain etc. Really disappointed

Wondering if the higher my FT4 goes, that's when the problems start.

Bloods being done next Thursday. Seeing Onc again on 24 November. Started this combi dose a week ago. Bloods then showed FT4 of 22 and FT3 of 3.

Thinking of asking for T3 only. They won't prescribe Armour or any NDT.

Is there anyone out there who's had to eliminate Thyroxine because it's been 'The problem' (especially migraines and body pain) and you've been better on T3 only ............??

Many thanks

8 Replies

Mazzamo, increase your T3 to 20mcg. It sounds like T3 was helping but your body is saying give me more. FT4 usually drops when you take T3.


Hi Clutter. Was thinking of doing this but will do it after my bloods on Thursday. Do you think 10 mcg in morning and 5 mcg afternoon and evening sound ok? Also thinking of reducing Thyroxine to 50 mcg when I do this.

Just a bit concerned because he startedme on 75 mcg Throxine and 20 mcg at one point. That sent my FT4 up to 18 and FT3 up to 10.2. Felt lousy. That's when he stopped the T3 because he thought I was converting after all. But then as you know, back on Throxine only, I had an FT4 of 22 and an FT3 of 3.

He's perplexed. I'm fed up:( Don't know which way to go xxx


Mazzamo, yes hang on until you have bloods drawn. If your FT3 is in range on 75mcg + 15mcg you won't need to reduce T4 to 50mcg. If FT3 is high reduce T4 to 50mcg/75mcg alternate days. Post your results when you have them and we'll advise.

When you increase T3 just add 5mcg to your 2nd dose.


Thanks Clutter. Will post results Friday,


Don't take any t3 or t4 until after the blood test as it will send the results high and meds may be reduced


Hi just posted a reply re this on earlier post. Had loads of probs on T4 only, combo and NDT. stopped T4 end of Sept. Got rid of bad a.m. h/aches. Now on T3 only. Early days and far from well but sticking with it. Problems exacerbated by low ferritin and low cortisol so makes it difficult raising meds. Doing CT3M or trying to. Ploughing way thru CT3M hndbk. Heavy going. I thk I can tolerate a small dose of thyroxine only possibly. I guess it builds up and gives me problems.


Hello again

Thanks for all your help and support.

Today I had results of bloods done at 2 pm. 5 mcg of T3 and 75 mcg Levothyroxine taken at 7 am. After 2 weeks on 75 mcg a day Thyroxine and 3 x 5 mcg T3 they are:

TSH <0.05. FT4 18 FT3 5.6 FT4 18.2.

Not sure that Levothyroxine is actually doing anything except just sitting there. I would think that if it were converting it would be lower than that.

I'm taking 5 mcg at 7 am, 2 pm and 9 pm. I find myself 'waiting' for the next dose and then I feel much better for about four hours. Mornings are not good and I've assumed that this could be being without T3 for 10 hours overnight, as opposed to the 7 hour dosing during the day.

Some improvement but still not well - weight,joint pain, constipation etc and low mood. Endo told me I could titrate until well as long as I don't go mad. He started me off on 10mcg T3 - 5 mcg am and 5 mcg pm. He said T3 at night would keep me awake - it doesn't and never has done. I sleep like a log for 8 - 10 hours.

I was going to increase 7 a.m. dose to 10 mcg in the hope that it would remove the residual symptoms which I think are hypo symptoms? I'm worried though that my TSH will go too low or FT3 too high. Also, don't know whether to reduce the Levothyroxine by 25 mcg at the same time. To be honest, I can't see the point i having it at all if it's not converting. I've thought all along that it's the thyroxine that I can't tolerate. Might it be necesary to stop the thyroxine altogether if the next step doesn't sort things out?

Is it possible to have hypo symptoms with a supressed TSH?

Would appreciate your comments as always.

Many thanks



Maureen, T4 and T3 shouldn't be taken until after your blood draw because it skews the readings by giving a false low TSH and false high FT3. Take your last dose of T4 24 hours prior to a blood draw and the last dose of T3 12 hours prior.

You haven't included lab ref ranges, so assuming the top FT4 is 22 and the top FT3 is 6.5, your results are good, just shy of the 'ideal' top 75% of range and don't indicate over medication. It took about 8 weeks after my bloods were good for me to *feel* good as hypo symptoms were still improving.

Your FT4 isn't just 'sitting there'. It will be converting even though it wasn't converting sufficiently without the addition of T3.

I think increasing T3 to 20mcg and continuing on 75mcg T4 is unlikely to send your FT3 over range but if you decide to increase T3 above 20mcg you should consider reducing T4 by 25mcg for every 10mcg of T3 you add.

Although you can feel some benefit immediately taking T3 it still takes 6/8 weeks for it to metabolise and work on your hypo symptoms. It can take a while to sort out when to take split doses to the best effect and you'll have to suck and see to find what suits you. You might try 10mcg T3 in the morning and the second 10mcg dose between 8/12 hours later. As the T3 is in your system now you should become less susceptible to slumps as the dose wears off. I take 75mcg T4 + 10mcg T3 in the morning and the second dose 20mcg T3 at bedtime.

If 75+20 doesn't work after a few weeks consider reducing your T4 and increasing T3. I personally prefer T4+T3 to T3 only but some people don't do well on any amount of T4.


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