I buy some of my NDT without a script, I take 120mg per day. My GP prescribes me 90mg a day. So I get the rest elsewhere. My GP doesn’t understand that TSH is suppressed on NDT, and I’m not going to be successful in educating him. My TSH was 0.01 on 150mg, but I reduced to 120mg about 5 or 6 weeks ago. I need to go get a blood test of just TSH for my GP, and I want my TSH to be between 1-2. Any ideas how long I need to not take NDT for? I skipped it two days ago, then took only 60mg yesterday. Should I skip another day then go? Or go for lab work tomorrow morning, with just one day skipped and one day half-dosed?
I see NDs as well which is where I get my complete bloodwork done. You can’t really get doctors here or switch if you have one, so before you tell me to educate my doc or switch, I’m confident this is the best plan for now.
Written by
CountryMidwife
To view profiles and participate in discussions please or .
The time it takes for TSH to rise after being very low varies enormously. For some, it does recover but tends to be slow. For others, it really never does.
The variability makes it pretty much impossible to guess.
I'm concerned that you are set on a course which will see you suffer from being under-dosed, very under-dosed at 60mg, but not seeing TSH rise sufficiently to satisfy your GP.
I don't have personal experience - and I hope others who do will also reply. But I did want to point out the possibility so that you can make your decisions with fairly open eyes.
If TSH has been very high or very low for a long time it can take a long time to come back to normal, if at all. When TSH is around normal levels it adjusts rapidly.Suppression of TSH by T3 really depends in dose, after all everyone makes (or used to make) T3. I think most people who need some form of T3 have conditions that require higher than normal T3 levels and it is this that leads to a low TSH. And of course some of us have a pituitary that simply doesn't secrete enough TSH. This van happen e.g. after Graves' or if high dose thyroid hormone has been taken for some time.
I would always try to keep your TSH from going low but in some cases there is no choice. A low TSH carries risks, clinical hypothyroidism carries greater risk as well as a miserable life.
Respectfully I disagree about a suppressed TSH when T3 is used. When you take T3, it will suppress your TSH, and often people are under dosed for this reason. Thank you for taking the time to reply. I’m going to go for blood tomorrow so we’ll see how much my TSH comes back up after one day skipped, one day half and one more day skipped!
This study ncbi.nlm.nih.gov/pmc/articl... shows that LT3 is about 3x as potent as LT4. They adjusted the doses to achieve very similar TSH levels. It may be that taking T3 once a day instead of 3x a day would 'knock' TSH down and it might stay down for a while - I'm purely guessing.
In your other post healthunlocked.com/thyroidu... you quote Free T3 6.1 Free T4 18.8 when on two grains NDT. You don't give the reference intervals but typical ones are fT3 3.5 - 6.5 and fT4 12.0 - 22.0. This would put your fT3 rather high in its interval and fT4 above average, both hormones contribute to suppressing TSH and the combined effect of your fT3 and fT4 might be sufficient to suppress TSH. It would depend on how long after your last dose you have the blood taken as T3 has a short half-life. Also, the manufacturers state one grain of NDT is equivalent to 100 mcg levothyroxine. So, two grains would be enough to suppress TSH in most people.
I'm being a nuisance because I think we need to use precise logic if we are to make advances, endocrinologists have proved incapable of logical reasoning.
I have noticed two cases where people need higher T3 levels that result in a very low TSH.
1. When the pituitary is underperforming, perhaps due to a period of thyrotoxicosis or rarely pituitary damage. Their TSH drops rapidly with a moderate amount of thyroid hormone, it's not truely suppressed because it wouldn't be so low in healthy people.
2. Endocrine disrupting chemicals(EDCs) can disrupt T3 binding to receptors in peripheral tissues but not in the pituitary. This gets very complex but essentially the hypothalamus and pituitary have different receptor types and bind hormone differently. You are in Canada, North America has high EDC levels, especially in the Great Lakes area.
We often forget that the pituitary and thyroid hormones work two ways, (1) thyroid hormone suppresses TSH and (2) TRH stimulates the pituitary to secrete TSH which stimulates secretion of thyroid hormone.
Your results before you started NDT are fascinating. First we should note that fT3 (in the blood, not as tablets) is 4x to 5x as potent as fT4. We can then look at the overall fT3 + fT4 figures from your previous post.
In primary hypothyroidism where the thyroid is failing TSH rises as fT4 + fT3 fall. This is not happening in your case (multiple fT3 x 4 to get fT4 equivalent). In fact we have the opposite: -
In Oct 6 and Jan 16 when your fT3 + fT4 are lowest your TSH is lowest.
The intermediate fT3 + fT4 from Apr 21 and Dec 7 give intermediate TSH.
The highest fT3 + fT4 from May 31 has the highest TSH.
To me this indicates the problem is insufficient TSH, not a failing thyroid. (We really need the reference intervals for your TSH, fT3 and fT4 results, without them we can't judge the numbers.)
There is evidence that TSH stimulates deiodinase (T4 to T3 conversion), especially type-2 deiodinase which regulates local T3 levels. In this case you would probably need more T3 to feel better. This is not deisirable as organs such as the heart may have too much hormone. It then comes down to striking a compromise between getting well enough to live reasonably well and not taking too much risk.
However, the ideal solution is to find out why your pituitary is under-performing. It is unlikely to be due to a damaged pituitary, that usually causes much more drastic reductions in TSH.
Do you have any other coexisting illnesses or depression? These can reduce TSH secretion, severe dieting can also lower TSH. The optimal approach is to find why your TSH appears to be lower than it should be (for your fT3, fT4 levels) and fix it.
Just to clarify I did say I take 2 grains (and I have for a bit), but at the last blood test (TSH 0.01) was taking 2 1/2 or 150mg.
After that blood test I came down to 120mg and have been there ever since as I feel best on 120mg. My BBT indicates I’m under dosed or still hypo, however I think it’s likely low cortisol, and not more NDT needed. My hair didn’t stop falling out until I went to 120mg.
My latest lab shows my FT3 is higher when my TSH is suppressed. My TSH does jump around on those tests, so it’s worth noting that I only began taking NDT around Dec 21. And I began a carnivore/ketogenic diet on Sept 5th, which lowered my TSH AND my FT3 and FT4. Being carnivore is the only way to not continue to gain weight, even on NDT.
My GP (primary) only tests TSH. A couple weeks after he started me on NDT he tested both TSH and FT4, (I had previously provided him my labs I paid for and obtained privately). I asked him to increase my dose from 60mg to 90 back in January, and he agreed. Because I also purchase Thyroid-S privately, I am on a higher dose than he is aware of. I want to stay at 120mg (again my TSH is going to be higher than it was on the last blood test), but I need to give him a TSH he doesn’t hate in order to have the script renewed.
I have excellent B12, folate and have addressed ferritin and D. I’m going to be getting DHEA progesterone, estradiol, testosterone, leptin, A1C, cortisol and fasting insulin tested privately in June (have to wait for the appropriate day of my cycle) in order to consider these things. I am still unable to lose weight, and my BBT fluctuates still. I’ve had multiple salivary cortisol tests done indicating the right curve but low levels that I haven’t been able to bring up despite months and about $2,000 of adrenal cortex supplements. So I’m wanting the blood draw on that marker simply to show either my GP or a functional doc for possible hydrocortisone script request.
The TSH jump from April to May 2023 was due to starting Lugol’s iodine; which is known to initially increase TSH, though it also will increase FT3 and FT4.
When I was on 60mg my TSH was 3.01.
the lab ranges in my area are:
LAB RANGE
TSH (0.2 - 6.5)
FT3 (3.0 - 6.5)
FT4 (10 - 25)
Ultimately, I do have a stash of NDT not from my GP so if he lowers my dose or doesn’t renew it, it doesn’t have to change my dose, but he’s not helping me get to the root of things with his own training.
I’ve also consulted a functional BHRT doc’s practice (so far only spoke to the nurse practitioner for an initial consult) and their preliminary advice was that I might need metformin or ozempic. Ozempic killed my aunt and I’m not interested in metformin.
Anyways I’ll be getting my TSH test in the morning, so will report back what happened to it after 2 days of skipping with one day of 60mg in the middle.
Gosh this is complicated! I might make an error as it's difficult to take it in.
Body temperature is not useful for monitoring thyroid status, their are too many variables that can affect it. It's true that with hypothyroidism one can feel really cold but this doesn't apply to all cases.
It's best not to take iodine unless it has been tested and deficiency has been confirmed. The effects are unpredictable, large doses of iodine used to be used to treat hyperthyroidism.
Your results from before you started thyroid hormone treatment confirm that your thyroid is capable of secreting normal(ish) amounts.
One point I forgot to mention is that TSH is not a single molecule like T3 or T4. TSH is a group of isoforms, molecules with similar structures but different levels of 'glycosylation'. I'm no good at chemistry (or biochemistry!) but essentially the more glycosylation the more bioactive TSH is. In simple terms bigger TSH molecules are more bioactive. The blood test measures how much TSH you have, it doesn't tell you how bioactive your TSH is.
You will see from your results (not March 12) that even though you had decent amounts of TSH it failed to stimulate the thryoid to make enough hormone, even when assisted with some NDT. This signals to me that you are secreting TSH with low bioactivity. As far as I know TSH bioactivity is only determined in research labs, it involves extracting TSH and seeing its effects on animal thyroid cells. So, there's no way you can have it tested.
When did you start to feel hypothyroid? Was there any illness, accident or events, physical or psychological around that time? ideally you would find the underlying casue and rectify it. If this can't be done I guess you will need higher doses of thyroid hormone but this does carry real risks.
Have you read anything by Doctor David Brownstein? I disagree on iodine, I think most people should supplement with it. I also disagree on basal body temp taken daily upon waking (specifically day 2/3 of a premenopausal woman’s cycle and then every day for anyone else.) this is from STTM, Dr Elizabeth Bright,Dr David Brownstein, Dr Broda Barnes.
Iodine is critical. Read Brownstein, Farrow, etc. Iodine is grossly underutilized and most people are deficient. I was raised in the Great Lakes glitter belt and now live in the Rocky Mountains (also a goiter belt).
I also have no concerns with a suppressed TSH when taking NDT (T4/T3).
I actually don’t think I need a higher NDT dose-I felt 150mg was a bit too high and have felt quite good on the 120mg. My DHEA, progesterone and cortisol are all low and need to be addressed. Retesting those and figuring out who to get those scripts from. But I think my NDT dose is good and could probably be lowered after all other hormones are optimized.
I’ve probably been hypo my whole life. Was a sleepy child, and was misdiagnosed with “Idiopathic Hypersomnia” as an adolescent and young adult.
I've always read the research and not books as I studied maths and so learnt to work from first principles, most relevant in thyroidology as so many doctors are clueless.I'm confused as I got the impression you were not doing well on your NDT. Your blood test results are unusual with TSH having a positive relationship with fT3 and fT4.
We will have to disagree about iodine but don't forget thyroid tablets contain a fair amount of iodine so factor this into your dosing.
To each their own. There’s a lot of articles sited in these books in addition to case studies, which I personally prefer.
As a health practitioner, I learn a lot from experience case studies and other practitioners over published studies alone. So many studies are funded by people with other interests, like pharmaceutical companies who don’t want people well. Iodine is pretty cheap.
Am I doing well on NDT? I am and I’m not. I’ve seen a lot of improvements but I don’t expect that NDT at any dose is going to fix the symptoms I still have. My BBT still indicates hypo which I suspect is due to low cortisol. My cycles, hair loss, energy are all markedly improved but I’m unable to lose weight which I do not believe can be resolved with thyroid hormones, rather I believe I need DHEA, progesterone and/or hydrocortisone, and am exploring those other hormonal imbalances to optimize my health.
My OP wasn’t about any of that (my symptoms or dosage etc) it was about how long it takes for TSH to come back up for a blood test to please my GP so I can keep getting my script.
Yes, coming back to your original question TSH usually responds rapidly but if it has been very high or very low for many months it can take a long time to recover.
Mine does not alter at all (0.2 ot 0.1) even when I went a week without any thyroid drugs (hospital). An alternative idea is to "confess" that you took your thyroid drugs that morning, being forgetful, which would give a false low TSH.
Unfortunately my doctor tells me to take me meds as normal, even on the day of bloodwork. (I don’t, of course), but he thinks I do. I did get a glutathione IV last night, and just read that high doses of glutathione can raise TSH, so here’s hoping! I am in the waiting room of the lab now, so we’ll see how it goes. Will update for sure.
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.
How quickly will my TSH rise when stopping T3?
After decreasing NDT because of adverse symptoms, how quickly can i increase again?
How long does it take for T3 (NDT) to be eliminated from the body?
Low tsh but is it result of taking NDT?
How long does it take to raise TSH?
