Low/Suppressed TSH: Hi just a quick question. Saw... - Thyroid UK

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Low/Suppressed TSH


Hi just a quick question. Saw Endo last week as my TSH is still very high at 54, so has increased my Levothyroxine by 25mg , so moving in right direction. When he mentioned my TSH and the importance of lowering it, he touched on the fact that a too low/ suppressed TSH was not a good thing, as puts you at risk of being hyper/oesto/ AF. I replied that I thought a suppressed/low TSH was ok providing your T3 was not above range. Was I right? He did not agree. Thanks

16 Replies

Why would a patient who had thyroid cancer be permitted to have a suppressed TSH? I don't think they succumb to become hypERthyroid.

If any of us take too much thyroid hormones, then we will have unpleasant symptoms and I doubt we'd continue and reduce dose ourselves.

This is from an expert on all hormones:-

"It's simple common sense. TSH is not a thyroid hormone and is not an appropriate

guide to thyroid replacement therapy. The hypothalamic-pituitary secretion of TSH did not evolve to tell physicians what dose of levothyroxine a person should swallow every day. A low or suppressed TSH on replacement therapy is not the same

thing as a low TSH in primary hyperthyroidism. If you have central hypothyroidism, the TSH will necessarily be low or completely suppressed on T4/T3 therapy; your physician must treat you according to symptoms and the free T4/free T3 levels.


Unfortunately it seems to be what the medical profession have been told.


Paulannttsmn in reply to shaws

Thank you for the link, very interesting reading.

Pascha1 in reply to shaws

Ive been hyperthyroid and I have also been over medicated the two have nothing in common, the over medication I had felt more like I had blood poisoning not anything like the way I felt when i was hyperthyroid and I went all the way to a thyroid toxic crisis with that so was at all levels of hyper at some stage...

shawsAdministrator in reply to Pascha1

It must be a horrible experience and I hope your doctor allows your TSH to be around 1 as quite a number in the UK, seem to think that up to 5 is o.k.

Pascha1 in reply to shaws

My TSH is stuck at 0.004

Was left in medicated with TSH of nearly 4 for 20 odd years and finally diagnosed 15 years ago But for years after diagnosed it was left with a TSH 4 and was by the looks of it very under medicated with 50mgs after 13 yrs I upped it my self just because I knew it would keep me awake up to 200mg over the couple of years I knew nothing about Hypo at all tbh ,now under Endo and have 100 T4 and 30mgs T3 and still room for improvement so changing Endo as mine isn’t listening x Dio2 heterozygous faulty gene .. and a di01 gene fault but that’s not believed

shawsAdministrator in reply to Pascha1

It's a pity they don't keep up with research and you can give him a copy of the following:-


If someone cannot convert T4 to T3, why not give them T3 alone as they might well have insufficient in their T3 receptor cells as they cannot convert T4 to T3.

To be on a dose of 50mcg of T4 for 13 years is disgraceful probably because your TSH was somewhere in the range so that satisfies many doctors who wont increase dose.

Pascha1 in reply to shaws

Thank you x

If your pituitary is performing well a suppressed TSH is associated with cardiac and bone problems. It may be the case that you have no choice, you have to have a very low TSH to get better. An example is thyroid cancer, you accept the risk of a suppressed TSH to avoid cancer returning. With a healthy pituitary the TSH gives an indication of the combined effects of T3 and T4.

You were right. :) But endos tend to not know very much about thyroid.


Of course he didn't agree. He was a doctor and they don't understand these things.

As long as you have your FT3 and FT4 in range it matters not if your TSH is suppressed. You are not hyper until your Frees are over range as well. In fact, if you're taking NDT or T3, you will have a suppressed TSH irrespective of your dose.

That said, there has been a huge shift in thinking about suppressing TSH in the treatment of Thyroid Cancer. It's now not thought to be necessary in the case of differentiated cancers - papillary, follicular. I was told this by my Oncologist who 5 years ago was insisting my TSH should be between 0.05 and 1.0. Now, because of the new guidelines and the (non-existent) risks associated with suppression, he's trying to persuade me to adjust my meds to give me a TSH of 2 - 3. I'm not having any of it so he's given up now. The only way I can achieve a TSH that high is by low levels (below range) of FT3 and FT4 which take me into the hypo range.

When oh when will they understand that people without a thyroid should not have TSH measured. It's meaningless. It's about as daft as measuring your oestrogen levels when you've had a total hysterectomy. Daft, daft, daft.

Paulannttsmn in reply to Hidden

Thank you so much for your replies, just shows how important the information we learn on here is and gives you some confidence to speak up and challenge some Endo/GPs views.


Suppressed TSH could very well be a problem without causing your family to drop down dead. Being a problem, with definite issues, doesn't always cause death even after years.

(Not an argument about TSH, but pointing out that the basis of the response is not convincing.)


The best thing for healthy heart and strong bones is active lifestyle and exercise.

For many, many people on replacement thyroid hormones, if dose is kept at a level where TSH is "within range " and not suppressed then they are too exhausted to even get off the sofa.

Almost any dose of T3 will suppress TSH

Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.

Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor

 please email Dionne at



The causes of osteoporosis do need better research and clarification.

We see two factors conflated with respect to thyroid. On the one hand, it is the high thyroid hormones found in hyperthyroidism or, possibly, over-medication. On the other hand, it is the low TSH.

It seems unlikely that both very low TSH and high thyroid hormone levels are independently causes of osteoporosis. Indeed, if they are, then that needs to be shown. But what we see most of the time is not convincing.

I find it stretching credulity to believe that the reduction of TSH from the bottom of its reference range, maybe 0.3?, to suppressed at 0.03 (a difference of 0.27) is regarded as having a serious effect. Whereas the increase from top of range, 4.00?, to 10.00 (a difference of 6.00) is taken as unimportant. Yes, I know the difference is in the opposite direction, but it is mere than twenty[1] times as large!

[1] Just actually worked it out, just over 22 times. Not a mere twenty times as first written. :-)

Sorry late reply, I know of two people who hav3 really crippling osteoporosis, they have never had any thyroid problems in their life, it runs in both their families parents and siblings have it,, so surely must be more genetic than tsh....

I as left hyper for years ending in thyroid toxic crisis (thyroid storm) when they discovered me my heart rate had been 180 bpm and had for about 3 years I know off and all my thyroi£ bloods were dangerously off scale, that was when I was 19 I’m now 55 and do not have oesteoporosis , so maybe in hyperthyroid doesn’t cause it and it’s genetic..

My TSH has been 0.004 for ages now, , even a dr I had never seen before when checked bloods to let me have print out and my T3 was over range @ 6.8 range 4.8 who ever the Gp was that signed them off said they are ok, I wasn’t happy with T3 being over, iI am coming to the conclusion no GPs in my surgery check properly, and I have seen Two Endos , not about TSH, 1st prescribed T3 with TSH 0.004 and second one swallowed hard when I told him it was that but still wrote to Gp to prescribe me NDT, but seems ccg won’t allow it, still waiting to hear back on appeal but they will probably use my TSH as one excuse plus it’s black listed :(

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