Thyroid UK
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Dose change 2 months ago - now feeling awful :(


2.5 months ago, my daily medication was changed on the back of these test results:

TSH 0.09 (ref 0.35 - 5.50)

Free T4 14.8 (ref 9.0 - 22.7)

Free T3 5.8 (ref 3.5 - 6.5)

I used to take daily: 75mcg T4 Levothyroxine & 10mcg T3 Liothyronine.

For the last 2.5 months I was told by my GP to reduce to 75mcg/ 50mcg T4 on alternate days (ie. reducing my T4 by 12.5mcg daily).

Gradually at 1st, but very marked the past 3 weeks my energy has taken a nosedive. I suffer with M.E. also, but on the previous dose I was on, I actually felt quite normal at times and had felt better than I had for years - was able to do so much more. I am now back to barely being able to stand for any length of time, feeling achy, weak and heavy-chested/ breathless.

On Friday I decided to have done a follow-up NHS blood test to see my levels now, of which I don't have the results of yet, and won't until later next week.

My question is; do you think it's possible for my health to take such a nosedive after such a tiny dose change? After feeling so much better on my previous dose, it's awful feeling this tired and weak again. I don't know whether to think its my thyroid levels though, or whether I should look for an answer elsewhere.

Many thanks in advance - hope its not a silly question! :/

13 Replies

It is not a silly question at all, and it is entirely possible that this small reduction is responsible for how you are feeling now.

It seems that your dose was reduced based on your TSH when your T4 is actually on the low side of normal and your T3 is fine. If your T3 is within range, there is no need to reduce your medication just because your TSH is low. TSH is usually low when you are being treated with anything containing T3 because the internal feedback mechanism is broken once you become hypothyroid. There was a recent paper showing that TSH doesn't respond to T4 and T3 levels in the way it should when the patient is hypothyroid. TSH seems to be ok for euthyroid and, to some extent, hyperthyroid patients but not at all for hypothyroid patients.

There are also other reasons why your TSH might be so low when your T4 and T3 are clearly within range. You could have low B12 levels, low iron or low cortisol. It would be worth getting these checked along with folate and vitamin D.

Many doctors reduce doses when TSH is too low because of the fear of atrial fibrillation or osteoporosis. This is a myth, provided T3 is normal (as yours is). Even the former chair of the British Thyroid Association, Dr Anthony Toft, says this! The BTA are responsible for the current guidelines on thyroid treatment.

Dr Toft also says in his book "Understanding Thyroid Disorders" that TSH should be below 1 and may need to be suppressed for the patient to be well. Also T4 should be at the top of the range or, in some cases, slightly above provided T3 is in the normal range. As your doctor is checking your T3, there is no reason for him to panic about a low TSH level. He has the evidence in front of him that you are ok on that dose.

My TSH is always low and my GP never reduced my dose. I hope you can persuade your GP to increase your dose again.

Carolyn x


Thank you Carolyn.

Thank you very much. X.

I think GP's fail to realise the massive change in quality of life that can result in their off the cuff decisions. I explained to him when he wanted to lower it that I felt so much better, had lost no weight (gained it if anything) and that I had no hyper symptoms - he replied; "yep, but still". Urgh!

I can feel I may have a battle on my hand with him - he's very closed-minded in his views.


They have no right to alter doses due to the TSH result. My TSH is 0.01 and am fine. This is what Dr Lowe says about adjusting doses. cursor to the following question dated January 25, 2002. This is an extract


Dr Lowe: Your observations don’t suggest to me that your pituitary gland isn’t functioning properly. In fact, your observations are consistent with what science tells us about a patient's T4 dose, her TSH level, and her metabolic health or lack of it. If the goal of a doctor is metabolic health for his patient, he has no scientific basis for adjusting her thyroid hormone dose by her TSH level. If the doctor is going to make the imprudent choice of treating the patient with T4 (rather than T3 or a T3/T4 combination), he should be aware of the relevant physiology and treat her on the basis of it. Otherwise, he's likely to ruin her health, as your doctor appears to be doing to yours.


That's really interesting yours is 0.01 and your fine. Goodness, he's obsessed with the TSH isn't he! Well, he is and he isn't - when it was 8 early last year and flagged as out by the lab, he didn't even contact me! It was left to me to ring for the result, look the levels up, then book an appointment with him (even though both the TSH & FT4 were flagged by the lab - T4 too low). I then asked him and he said 'well yes, maybe could be a slight problem there, not very significant'! At the time I felt awful and freezing cold.


I only know from my own experience that a tiny change in levo dose has big effects on how I feel. I would be asking why they had to decrease it. Hope you can get it sorted


That's good to know as I was also wondering whether such a tiny dose change could have such an impact on my health.

He changed the dose purely on the TSH being flagged by the lab - he acknowledged the other 2 were in range & fine.


My tsh is 0.2 and I feel fine. My gp seems happy with this too. It's been as low as 0.01 before and I still felt fine. When I dropped my dose by 12.5 mcg my tsh shot up to 2.7 and I felt terrible. Certainly in my case, there's a arrow therapeutic range. I would ask / demand to go back to the dose that suits you best.


Thank you - that info's really helped with your personal experience/ levels. I will go back ... And be firm! Thanks again.


BTW. I supplement with methyl folate, methylcobalamin, vitamin D & quite a few others. Odd maybe then that my TSH is so low, but my T4/T3 mid range?


I too had my dose reduced by 12.5 this week as the Endo thought my TSH was too low (I have no thyroid at all) and they never even checked for T3 and T4. 4 days after reducing the dose I am much more tired and in a deal of pain.

The reduction was because a) by low TSH and b) heart rate. I am still trying to work out what to do next as I feel between a rock and a hard place.


Hi. Could you ask your endo to test for the others, or is he/she a bit unapproachable ? Did you feel ok even though your TSH was non detectable and your heart rate (presumably) high?


I am not going back to this Endo - she would double her knowledge if she just came on this site. I don't want to pay her again (even though I can claim in back - I am in France and it is a bit different here). I will see if there is another Endo (I will ask GP if he can recommend) or I will try to get a UK private appointment or may just try to do it myself with GP.

There is no point writing a cheque for poor help - that makes me feel even worse.

Fingers crossed that we (and all these other people suffering with this) get this sorted



My latest blood results are back:

TSH: 0.23 ref: 0.35 - 5.50

T4: 12.4. ref: 9.0 - 22.7

My GP has already rung to say he wants to see me as I'm taking too much and my results are too high!!! Lab flagged it as 'slightly raised'.


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