I saw a ‘hormone specialist’ GP today. Again she tried to tell me I need to reduce my levothyroxine because of my suppressed TSH. Only saw her because she’s meant to be good with HRT, but she’s gone mad about my TSH.
My FT4 is only 48-% through range, so if anything, I’d like to increase my levo!
I tried T3 but it didn’t really work, so gave it up about 3 months ago. My TSH is obviously still suppressed. She’s having a meltdown about it. I suggested a dexa scan and heart tests if she’s that bothered. Told her I wasn’t concerned at all and that it would take some time to correct. Apparently she knows because she used to work in the endocrine department at the hospital. Seems she doesn’t know a thing because she said they’d only usually test TSH, sigh.
How long does TSH take to return to normal levels. I don’t have my records to hand but it’s currently about 0.008 and was always 1-4 ish before I tried T3.
thank you.
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CornishChick
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There's absolutely no way to know how long. The pituitary takes it's own sweet time. But, the longer it's been suppressed, the longer it takes to rise. So, how long were you on T3? And how long have you been off it?
Thank you. I don’t have my notes, but took T3 on and off for around 3-4 years. Only a small amount, max 25 mcg a day. Was always towards the top or just over range. Dabbled with doses and tried stopping but never felt any different. Didn’t feel I actually needed T3, was just another thing to knock off the list.
I have not taken any for approximately 2-3 months.
25 mcg T3 is not a small dose. Not if you were also taking levo.
Well, 2 - 3 months is not long, so it probably needs more time. But, if your TSH was suppressed for 4 years, there is always the possibility that it won't rise again. Not if the HPT axis has been down-graded.
But, there's not reason to think that the OP has any pituitary issues from what she's said so far. It could just be that the HPT axis has been down-graded by long-term suppressed TSH. It happens.
There is a system of signalling between these three glands in a healthy person:
- the thyroid makes thyroid hormone
- the pituitary and hypothalamus detect the amount of thyroid hormone in the blood
- when thyroid hormone levels drop, the hypothalamus 'instructs' the pituitary to produce more TSH (Thyroid Stimulating Hormone)
- when there is enough thyroid hormone in the blood again, the hypothalamus stops signalling the pituitary so the pituitary makes less TSH.
We call this the Feedback Link.
However, when the person is hypo, and taking exogenous thyroid hormone, the link doesn't work quite as efficiently. And when the person is taking exogenous T3, the TSH becomes suppressed quite quickly. This is because the pituitary gets the lion's share of the T3, so ceases making TSH, whilst often leaving other tissues with insufficient T3. So, the TSH can be suppressed but the person can still have hypo symptoms.
If this goes on for long enough it becomes the 'new norm' - it becomes down-graded - and the pituitary stops making any TSH, even when thyroid hormone levels are low. Doesn't always happen - it didn't happen to me - but it often can, especially in people who have had Graves', with very high levels of T3.
The process I explained above has nothing to do with symptoms. TSH doesn't cause symptoms. It's T3, when too high or too low, that causes symptoms.
Besides, you probably did have some but didn't realise they were caused by hypo. The list of symptoms is long, like over 400 recognised symptoms. They can occur anywhere and everywhere in the body.
Possibly never. Even in a best case scenario it can take several months but the truth is that a suppressed TSH may never return to “normal” levels.
And that’s something your doctor ought to know without you having to tell her but sadly so many doctors don’t seem to do any reading about thyroid conditions, they just try to read thyroid blood tests at face value.
She certainly shouldn’t be freaking out but she absolutely should be going by FT4 and FT3 levels to ascertain whether you’re on sufficient thyroid hormone replacement.
oh crikey I didn’t realise that. Why might it never return to normal?
She stated that they only go off TSH and she could only see my FT4 because my TSH was so dire. I know this is wrong, but it’s difficult to explain this to a GP who thinks she’s an endocrine expert.
I take 125mcg of levothyroxine. I haven’t tried splitting the dose. May I ask how this might help please? I will try if you think it’s worth a shot.
Yes am constantly having FT4 tested and periodically FT3. FT3 was consistently top of range and a bit over at times when on T3.
Have had vitamins tested multiple times. Am happy with everything except my ferritin which has gone down again. I am massively into nutrition, so know exactly what to eat, and although I can no longer face liver pate each week, everything else in my diet is good including red meat three times a week.
I’ve also been taking an iron supplement to try and help, so was surprised to see it had gone down from 42 in March 23 to 39 at the end of June 23.
From memory, my TSH is around 0.008 (0.35 being bottom range).
I will try Three Arrows thanks once I’ve used up the ones I’ve bought. Am a bit confused in the thread where is best to purchase from, do you know please?
I spilt my levo dose yesterday and will definitely try to do that. So difficult though with other meds and eating- I’m a grazer!
Thank you. The reason I struggle is with insomnia, I set my alarm for 730, and have to get breakfast and out the door on the school run for 830. I couldn’t leave the house without food, I’d feel faint.
At bedtime I take LDN, magnesium and antihistamine to help me sleep. I didn’t realise magnesium was 4 hours, so thanks for that.
Hi , I'd not reduce your levothyroxine if you are well on it. If your fT4 is mid range then I'd Stick to that dose. TSH will be suppressed even when on levothyroxine alone. Your GP knows nothing. She is making outrageous claims. I would definitely challenge her ideas regards onlybtesting the TSH. As an endocrinologist would actually test all of the panel for thyroid if they're a good endocrinologist. So that would be TAH, fT4 and fT3. As well as other markers such as bone profile which includes Vit D3 levels. FBC, cortisol levels, iron levels and pituitary tests too !! An endocrinologist would also test your TRab, and Tpo levels too for antibodies. Don't fall for the outrageous scare tactics. And tell her or ask her if , she is threatening you !! If she continues then you will have to report her ! Or refuse to see her again. I've refused to see a particular GP in my surgery. So , it happens. They get too big for their boots !! :/ You know when you are not well on thyroid meds. Good luck. Stand firm. X
Thank you for your support. I tried to rebook my follow up with my original brilliant GP, but he’s booked up until October and further dates yet to be released!
Why TSH remains lower for quite along while following episodes of hyperthyroidism / overmedication .... or any T3 use ** .
it is due (at least partly) to a mechanism called 'Hysteresis'.
"Hysteresis is a Greek term that means “shortcoming” and “to be late" ..... Although the phenomenon of persistent TSH suppression and elevation with consequent lagging of thyrotroph recovery following severe thyrotoxicosis and hypothyroidism had been observed for many years, the first formal description of hysteresis involving the HPT axis was enunciated in 2007" (Qoute from paper below)
healthunlocked.com/thyroidu... showing-the-delay-in-tsh-responses-to-thyroid-hormone-changes "a good paper showing that TSH delays its response to thyroid hormone changes, sometimes over a very long time indeed. Should be useful in demonstrating to GP's that suppressed TSH will not easily respond to T4 changes and that they should not expect to see changes in the medium term - ie don't further reduce doses just because the TSH hasn't changed".
healthunlocked.com/thyroidu... tsh-does-not-respond-quickly-to-changes-in-thyroid-hormone-levels "This paper demonstrates how TSH changes lag well behind changes in FT4/3 levels. The longer the dwell time of a particular set of FT4 and FT3 concentrations the longer the lag in TSH response. Useful to provide evidence that TSH is not a credible test if applied wrongly at the wrong time"
Both posts are discussing this same paper:
frontiersin.org/articles/10...A Review of the Phenomenon of Hysteresis in the Hypothalamus–Pituitary–Thyroid Axis Melvin Khee-Shing Leow
"2.5. Interpretation Errors from Physiological Memory Effects or Hysteresis
From clinical experience, we learned that healthy set points are expected in a certain area of the reference ranges of [FT4] and [TSH]. However, in cases of severe hyper- or hypothyroid conditions, the disordered physiology needs a significant amount of time to restore the system to normal system operation [4].
This “memory effect” in which a system is dependent not only on its current state but also on its former environment is recognized as hysteresis and is a phenomenon well characterized in many areas of physics such as what has been observed and analyzed in the magnetization curves of ferromagnetic materials. In the realm of physiology and medicine, hysteresis has also been encountered in pulmonary mechanics, bladder smooth muscle stretch, and even calcium-parathyroid hormone relationship [10–12].
With thyroid physiology, hysteresis causes a shift of the original characteristic over the horizontal axis, in this case the [FT4] axis. When the HPT axis encounters sustained elevated concentrations of [FT4] well above the extreme of the upper normal limit (i.e., thyrotoxicosis), it is consistently observed that the recovery response of [TSH] lags behind that of [FT4] with definitive treatment of the thyrotoxicosis before [TSH] will be detectable again even when [FT4] declines to subnormal levels. Evidently, the system “remembers” the huge amount of [FT4] and needs time to remove the effects. This is actually a beneficial adaptive feature that is evolutionarily conserved to protect the organism in case [FT4] should suddenly escalate rapidly without restraint, since the [TSH] will remain low and will not add undue further stimulation to the thyroid. When the [TSH] response is detectable again, we see a shift of the original HP characteristic to the lower end of the range of the [FT4] scale.
A similar effect is observable after a long standing hypothyroid condition with [FT4] concentrations depressed far below the lower normal limit. In this case, the [TSH] normalization response lags behind the recovery of [FT4] such that [TSH] may still remain in the supranormal levels despite [FT4] having achieved normal or even relatively high levels due to the HP curve being shifted to the higher range of the [FT4] values. Again, this hysteresis represents a protective mechanism as the persistently elevated [TSH] provides a “buffer” of additional thyroid stimulation in case [FT4] should suddenly diminish to negligible from an unpredictable loss of exogenous T4 supply."
also .... the Pituitary can physically shrink if it hasn't been asked to make any TSH for along time .. it can take along time to get back to it's previous size, so even when it should be making more TSH , it can't , until it has got bigger again. healthunlocked.com/thyroidu... why-tsh-only-responds-to-change-of-circumstances-after-a-long-delay-if-at-all ( link to paper is half way down replies)
he gives some links to studies of how many months it can take TSH to recover .
(his reply starts ~"I will be away for a few weeks so may not be able to follow up further queries. Studies into a down -regulated axis are ....... TSH Time to Recover studies: .......... " )
** To understand why 'any T3 use' could trigger hysteresis even though the dose was not causing overmedication :
See the first reply on this post , it links to information explaining how T3 has a relatively greater suppressive effect on TSH than T4 does : healthunlocked.com/thyroidu.... tsh-is-just-the-opinion-of-your-pituitary-about-your-dose-but-your-pituitarys-opinion-is-a-bit-warped-once-you-take-thyroid-hormone.
Thanks so much Tatty I did try looking for an article that explains things more clearly—I’ve read lots of stuff about this over the years but research articles often tend to be a bit geek-speak and not especially helpful to those who just need a simple answer to “but why??“. This is good. 👍
Wish our GPs had proper training on this stuff. Alas, not gonna happen any time soon.
Hi CC- Have you had your adrenal function checked? You have had good doses of thyroid without much improvement. Adrenals are vital to your wellbeing, how well thyroid is utilized and often overlooked. I've been in same boat as you with great thyroid numbers, suppressed TSH and still don't feel all that well. Tried many different thyroid protocols over the years. Turns out I have lowish cortisol and below range DHEA so adrenals are stuggling. Hope you feel well soon.
Thank you for your reply. I have low cortisol on blood tests and low ish on saliva tests. I also have below range DHEA on saliva tests.
My DHEA-S was very bottom of range on bloods. I started taking pregnenolone and cortisol increased, I haven’t had a DHEA-S retest. However, I started HRT in May 23, mainly in an attempt to improve my bottom of range testosterone - don’t have any menopausal symptoms. I was then told by my a private hormone doctor to stop the pregnenalone to see if the HRT improved things.
I very much suspect adrenal issues. I definitely improve with an adrenal cocktail if I have a mid afternoon slump.
I passed the short synacthen test and just had another. Suspect will pass that, but am in the range just out of Addisons crisis which the NHS don’t seem to bother about.
Are there any other tests you’re referring to please? Thank you.
I agree with your suspicions that you likely have adrenal issues. Probably some degree of secondary adrenal insufficiency. Hopefully the pregnenolone will help to raise cortisol levels. A small dose of DHEA ( perhaps 5 mg twice per day) could help as well. T3 typically reduces overall cortisol levels by increasing its clearance rate. Tricky stuff for sure, but you’ve tried various thyroid protocols with excellent numbers and still no resolution of symptoms; therefore adrenal issues seem like a logical conclusion. All this stuff about vitamin levels and %s of range for thyroid won’t matter much of your adrenals are impaired.
Thanks tattybogle - just what I need to convince my GP that dropping my dose even further will not effect my TSH. I refused a drop as my T4 is too low at 14.8 anyway. This fixation on TSH does us all harm!
You are right not to be worried about your TSH being suppressed. As long as you are on thyroid meds you never need to worry about that test. It will always be suppressed.
For anyone reading this, here is my advice after 30+ years taking thyroid meds:
STOP chasing blood levels. The main thing that is of utmost importance is how you FEEL!
I’ve been working with my GP, who is awesome, and we agreed not to care about the TSH. We look at primarily Free T3 and Free T4, but mostly free T3.
MANY doctors are clueless about thyroid. My recommendation to everyone is to not take anything synthetic, only take bio-identical NDT. Why? Well, NDT has T1, T2, T3 and T4. N studies have been done on the first 2 and they don’t know how much it helps us or not.
I do recommend taking a T3 dose in addition to an NDT if you don’t feel as good as you could. It is a THEORY that your body converts T4 into T3. If you’re hypo. Take a T3.
WE ARE THE CEOS OF OUR OWN BODY. Don’t let dumb doctors tell you you SHOULD feel good when you don’t.
On the NHS—extremely unlikely. There’s been quite a hatchet job done on NDT over the years.
However, quite a few more folk these days are successfully getting levothyroxine AND liothyronine prescribed (it helps that liothyronine has come down in price recently—it was ridiculously expensive for years).
But in the first instance you could do with someone prescribing levothyroxine according to ALL the blood tests, not just TSH. That would get you a long way towards feeling a lot better. If the GP in your surgery is only looking at TSH, it might be worth seeing if there’s another doctor in the practice prepared to see things differently.
Thank you. I am going back to my original GP who understood my suppressed TSH. I only saw the other GP as she was a hormone HRT specialist. Unfortunately turns out she thinks she’s a thyroid specialist, and spent both HRT consultations trying to get me to agree to reduce my levothyroxine. With FT4 at 48% through range, I wasn’t going to agree.
She’s put it all in my notes now, so I am worried the other GP will take her word, thinking she’s a specialist. We just don’t need this stress whilst trying to stay well.
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