Barbara Lougheed, the author of Tired Thyroid asserts that TSH isn’t useless (her words, not mine) because it triggers T4 to T3 conversion at cellular level. I’ve never read that anywhere, in fact the importance of TSH is often downplayed if it’s low as a result of thyroid replacement treatment, unless linking it to potentially dangerous consequences if FT4 is simultaneously high. I’m not for one minute suggesting she’s right or wrong, I’m just surprised that I’ve never heard that before
I’ve had a quick search but can’t find anything yet that confirms what she says. Anyone have anything they can share please because I think it might be worth discussing misconceptions to get some clarification from those who understand
Thanks
Written by
Noelnoel
To view profiles and participate in discussions please or .
If you get deeply enough into TSH, you find there are lots of interesting observations. Such as that there are multiple isoforms of TSH. And there can be antibodies to TSH.
Both of those factors can affect the results from TSH tests.
Also it is important to remember that TSH secretion isn't solely caused by thyroid hormone levels in the blood. But also TRH released from the hypothalamus.
Knowing that TSH has some effect on T4 conversion is fine. But it doesn't help those who have suppressed TSH which they can't do anything about. For example, that often happens for at least months, possibly years or forever, after a long period of hyperthyroidism.
It is interesting that TSH affects conversion. It is important. But the prime issue we have is excessive reliance on TSH only combined with willingness to see patients definitively low in thyroid hormone just to try to see TSH rise.
helvella is right that those of us with low TSH just have to accept that influence on conversion is gone.
I was originally hyperthyroid. After RAI I spent years feeling ill on levo only. On 100mcg levo my TSH was under range 0.19 and my ft4 was at 60%. My ft3 was only at 17%.
Adding in 7.5mcg liothyronine daily has solved the conversion problem and brought my ft3 up to 72%. However my TSH is now undetectable and the only way to increase it would be to stop liothyronine and reduce my levo dose to 50mcg or 25mcg per day which would make me very ill........
Hi, I’ve had a total thyroidectomy many years ago. I was ill for 18 months before it was discovered I didn’t convert T4 to T3 properly. I was then given liothyronine in combination with thyroxine., this was in 2004. In 2015 a gp took it upon herself to reduce both doses because of my very low TSH ( 0.01) on a comment on my blood results. I ended up leaving work so ill. I saw an endocrinologist later the same year & he told me that no matter how much T3 dose is reduced the TSH will never recover as it has been permanently suppressed by the T3. Not sure if this applies to everyone if they still have a thyroid but it does to patients like me. All in all I wished I’d never had to have my thyroid removed I’ve never felt well since & 21 years is a long time of feeling like that.
The human body really is a complicated thing. Keep up the good work everyone it does help.
You sound about the same as me , not feeling right,I had to have radio active iodine treatment, about 30 years ago, was told it would bring my thyroid back to normal , that’s a laugh, hope you get there in the end
Great post Lalatoot. In my experience with having TSH in normal range or feeling *Optimal * with adding T3 and having very low TSH. It's not a question which way I'm going.
Great experience for the rest of us to relate to. Have you always remained at 7.5mcg or did you have to experiment to find your ‘sweet spot’? I am asking because I have started (third time around) on T3. This time I am monitoring temperature, pulse, and blood pressure, to see what is happening. I am only on 2.5mcgs but already I see a steady improvement in both temperature and pulse. I am pretty sure I will need more at some point!
It took me 2 years of slow adjustments. Because the endo decided I should be on 50mcg levo and 20 liothyronine I worked my way to that dose first. It didn't suit me. I then spent the next 2 years decreasing lio and increasing levo one thing at a time. 100mcg levo and 7.5mcg lio seemed best. Now been on that 2 years. I monitor my resting heart rate as a simple guide.
Lalatoot during your slow adjustments of increasing levo and decreasing lio over the two years, curious if you found the progress/improvement to be linear e.g. did further increasing or decreasing your dose towards the direction of the sweet spot you eventually found always result in improvement? Or, did you ever have the experience that sometimes changing your dose to get closer to your sweet spot made you feel worse (even if you stuck with the new dose a full 2-3 months) but then with the next change in the same direction you would feel better?
I know for people who are starting thyroid hormone things can feel much worse on a low dose until they get to a high enough dose that things finally start to improve, but am wondering if people whose bodies have been acclimated to the hormones for an extended time already have the same experience when needing to change things up (whether increasing or decreasing) to find wellness again. (Knowing your experience is unique to you and everyone is different).
Oh it was truly awful at times. The body does not like change. But during the 2 years of adjustments I really got to know what effect I could expect a change to have on thyroid blood levels. I could pretty well judge what my results would be. But what I never knew was, what effect the change and those blood results would have on symptoms.I could have continued longer than 2 years making changes but I came to realise that some improvements might only come from being on a stable dose longer than 3 months . And indeed things have continued to improve.
Thanks Lalatoof. I hate that nothing is ever simple and straightforward dealing with our thyroids - definitely an art and not a science! Can umderstand your point about stability and how that aspect makes it extra tricky to find the right dose - Ive experienced the l benefits of stability in my own journey as well.
Glad you were able to get to a point of feeling relatively well (and love hearing that you continue to improve).
Yes!Yes!Yes! The only thing that I figured out from my experiences is that I need a certain amount of T4 and some T3 . I was dosed for years after my TT by TSH and felt awful. Now I trust how I feel . Run labs FT4 FT3. TSH is very low. And it doesn't concern me. I put more emphasis on my FT4 FT3 and most of all what my body is telling me.
Yes they can bleat on all they like about TSH but if they make you ill following a load of outdated TSH dogma, it’s just a nonsense. We should not feel ill all the time we should feel well - it’s just plain common sense, illness is your body’s way of telling you something is not right. I’m totally with you if it feels right it IS right!
The thyroid is just such an interesting subject, new things are being learned all the time!
Could this be why some people still manage to lead a fairly normal life with a massively elevated TSH?
But then why can't others like myself manage similarly? I wonder if there is yet more components to it.
In the end does it matter greatly if, even with a TSH in the normal (or above normal) range you are terribly sick?
I wonder if this is part of the justification for why some doctors (Bianco etc) are saying T3 should only be administered till the point the TSH reaches just above the bottom of the range. I find that dangerous as you are taking one metric and making a lot of assumptions about how it works in the individual. As Helvella says TSH expression is affected by TRH released from the hypothalamus and so is it possible that you might have a chicken and egg scenario. The hypothalamus needs T3 and so TRH levels might be affected in itself by you not having enough T3 levels in your blood.
I don’t think there can be many people with a massively elevated TSH living a normal life. I can assure you I was completely demented with 110. I wonder if it has been studied? Probably not.
tattybogle had an interesting graph of TSH distribution in a normal population and no one on it is over 4, the distribution curve for TSH is not bell shaped but asymmetrical tending to the lower values with most people having a TSH around or below 1.5 (that’s with a fully functioning thyroid).
I can only think that the thyroid is doing overtime on T4 to T3 conversion as it dies, and this might allow some to escape serious symptoms for a while, but once it croaks all hell breaks loose. I had a multitude of symptoms for years before mine finally gave up the ghost. But I have no idea what my TSH was, as no one thought to test it. I had a life but it was a pretty grim one - hideously depressed and lurching from one health problem to another. But no one listened when I asked could it be thyroid related. It got very out of control, I thought I was a hypochondriac I had been gaslighted so much and my mind was enfeebled by it, so just suffered all that hell in silence, but I wasn’t imagining any of it!
It surely has to better to treat as early as possible and dose until symptoms cease. Like they did in the old days with NDT. I think they should use NDT, not vilify it and make access to it by NHS prescription impossible. They should let us choose if we take it or Levothyroxine or synthetic combination. I bet a large cohort would go for the NDT or T4/T3 combination therapy. The evidence is tending heavily towards this being the best option not Levothyroxine….and that would disable TSH as the be all and end all of dosing protocol, if the likes of Bianco actually understood the supremacy of T3 in all this, but they seem determined to keep applying the wrong metric because they don’t really comprehend the latest research they just think they are cutting edge but they are nothing more than old school TSH worshippers dressed up as supposed novel thinkers.
But do they really have such high TSH as it appears?
How many are tested for macro-TSH?
How many have the TSH analysed further as to which isoform(s)?
And if the thyroid is producing as much as it can, working flat out, and that still isn't as much as you need, then there is no obvious reason for it ever to stop rising.
I suspect that, when healthy, our pituitaries can only produce enough to reach a modest level - say 10 or maybe 20. And it takes a long time for the pituitary to enlarge enough to reach the heights of 100 and more. But as it is doing that, the actual thyroid hormone levels might not be quite as low as we obviously assume.
And so that is one reason why t4 monotherapy can be sub optimal - because the tsh is suppressed which lowers the t4 to t3 conversion so you may end up with a t3 level which is suboptimal for the patient and the medic declaring " but I've cured you" looking at the tsh result.
The paradox for our endos & GP's is having enough thyroid meds to achieve well being often results in a low/suppressed TSH for many, because the loss of the thyroid gland and initiation of of thyroid hormone dosing alters/skews the natural TSH-FT3-FT4 hormone relationship.
This disjoint is one aspect that deiogenes and the team have highlighted in several papers, and TSH receptors have been found in bones but Bianco says it has little importance in the body, apart from influencing the deiodinases (conversion enzymes).
Having a little T3 in meds increases conversion of itself, and it’s an equation medics can not get their head around, but the reduction in TSH and subsequent loss of T4 - T3 conversion becomes irrelevant when we have adequate thyroid hormone because we don’t need TSH within range for that assistance in conversion due to receiving enough T3 from our meds.
In my experience splitting my daily levo and liothironine into four doses (at 7 A. M., 12, 6 P. M. AND MIDNIGHT) allows ne to keep my ft3 and ft4 midrange and my TSH in the low normal range. If I take the same amount of levo all in the morning I get approximately the same ft3 and fr4 but lower/suporessed TSH. I think this may be because TSH responds to peaks of thyroid hormones more than to average values.
I am very sensitive to medications and I get headaches and other symptoms if I take my thyroid medication in one daily dose. So I tried different combinations and found that out.
I only take vit D + sometines vit K at 8:30 with breakfast. I eat a lot of vegetables, eggs, fish, red meat and cheese so I'm fine with iron, calcium, vit b12 and most other nutrients and vitanin levels. I find that when my ft3 and ft4 are midrange food is a good enough source. If I am hypo then I become anemic.Also, taking some levo and lio at night feeds the adrenals at a time when they are active, so I no longer have low cortisol.
I presume then that you test from time to time to check core nutrients and cortisol
Apparently Vit D should always be taken with K2 and also magnesium should feature in there somewhere. Just passing on the advice from the forum and what I’ve read elsewhere, in case you were unaware
Thanks. My liver is nit in perfect conditions and I cannot take much vit. K2. Also I've heard that vitamins A and E should be taken with D and K2. I'm actually wondering whether we should take less supplenents and eat more fat instead, since many liposoluble vitamins seem to have to be taken together.
I’m right there with you on eating more fat. Definitely we should eat more good fat but there’s a problem with absorption of nutrients in hypothyroidsm and many of us cannot get optimally nourished by just eating well
I found this out quite early because of this forum. My diet is exemplary, so I thought I didn’t need to bother with supplements or testing but I was shocked when I took the various tests advised on here. Everything was low. I honestly couldn’t believe it and there was I thinking there couldn’t possibly be any deficiencies And then I began to wonder just how long I’d been malnourished for and how much havoc had been wreaked on my body because I was blissfully unaware that my “perfect” diet wasn’t enough to keep me well. How ignorant and smug of me
It does beg the question though: if we can’t absorb nutrients from food how do we manage to absorb the nutrients in supplements? My simple way of thinking has come to the conclusion that It must be because if the dose is high enough and soluble enough then some at least gets absorbed. A bit like those hypos who don’t do well on T4 and instead have to have large doses of T3 to bombard the cells to gain entry. Maybe. Possibly. Perhaps
Yes it is an interesting question. Thanks for your suggestions. I actually don't get tested for all I should. My lifestile is quite irregular and I've been busy trying to figure out my t3, t4 and vitanin D and K2 doses and diet. I am now gluten and cow's milk free, I eat very little carbs and I have found out I have a few food intolerances. But I will need to get tested for other vitamins and stuff. Forums like this one are precious for us all!
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
What is the tsh reference range for combined t3 and t4 therapy?
Could anyone tell me the benefit of having both TT4 and Free T4 tested please…just looking at differences in tests and prices please?
I read that it isn't advisable to take thyroxine with suppressed TSH and T4! 
High TSH on Levo
Range for tsh that you wonderful people think is optimum range 
