How long after quitting NDT would I be back to ... - Thyroid UK

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How long after quitting NDT would I be back to baseline?


I'm still struggling with my NDT dose, I get heart palpitations in the evening, so do think I am over medicated, I take 2 grains at 7am, and 1 grain at 3pm.

I’m pretty sure the T3 is causing me problems, as it sends my body into overdrive, if I dose 3 grains it alleviates some symptoms, but causes my heart rate to go through the roof. My T4 is low but I suspect my T3 is too high.

I’m wondering if I could try and taper off NDT, how long would it take to get back to baseline, for my body to start trying to produce T4, from being completely suppressed.

I went on after my body crashed, but I also had to go on Testosterone replacement therapy, so as I will still be on that I’m wondering if my body will have a chance of recovering as I do not have a definite disease, there was a signalling problem.

41 Replies

'as I do not have a definite disease....there was a signalling problem'....does this mean you were not diagnosed with hypothyroidism, nor Hashimoto's disease? Before I read this bit at the end I was going to ask if you had been on T4/levothyroxin etc before NDT, and whether your blood tests showed you had a conversion problem. If so the fixed T4 to T3 in NDT might not be in the ratio that suits your body, as you suspect 'my T4 is low but suspect my T3 is too high'. I got palpitations on adding T3 to T4, but they went after three weeks and also as the dose went up to 25 mcg T3 with 75 mcg T4.

I was diagnosed with hypothyroidism, my TSH was high, and T4 below range. It is a complicated situation but my hormones were in the gutter due to a reaction to finasteride. But I think maybe my body would be able to recover now as my other hormones have been kept at good levels for months now.

Yes I don't think I have a conversion problem at all, and the T4 and T3 are definitely at the wrong levels. My last blood test showed T4 low but T3 very high. I know that T3 is the culprit but if I lower my NDT dosage too much my dry eyes/blepharitis flares up.

I think I should try and get on T4 or taper off completely as my body is over stimulated, and every evening is very uncomfortable. But that would mean finding a new doctor and having to tinker about for a while, when I have only just started living again, and am trying to get back into society after an illness hiatus.

My blood tests before I went on NDT were


FT4 10.7 (12-22)

FT3 3.4 (3.1 - 6.8)

but the 2 years before I crashed my TSH was 3.3 or so and the Frees a bit low.

Did your palpitations go away without lowering your dose?

Yes palpitations, high pulse and Bp disappeared overnight to ' normal', certainly didn't lower T3 dose as then or soon after on 25 mcg T3 and 75 mcg levo; after blood test now raising levo up again too to 125 mcg. T3 seems to me to be a very difficult thyroid 'med' to use and adjust compared to T4, I've never taken NDT to compare. I did experiment with the time of day I took the T3/T4 combo...some take them at bedtime, others 5-6 am and then go back to sleep, others 1 hour before breakfast; some take all their T3 in one dose with T4, others take some with all their T4 and split the rest of the T3 into another 1( like me) or up to another 4 doses thru out the day( don't know how they eat/ drink, take supplements, other drugs as you have to leave 2-4 hours after some before you take thyroid 'meds'). Just be patient and try to see what suits.

By 'signalling problem', do you mean you had low TSH with low Frees? If so, it was a pituitary problem you had, rather than a thyroid problem. Why would you think that has changed? If your pituitary cannot produce enough TSH to stimulate the thyroid to make hormone, it's never going to be able to make enough T4 on its own - and it's your thyroid that makes thyroid hormone, not your body. :)

I had high TSH, with low T4 and T3, especially T3. There was no genetic disposition. I took finasteride (blocks testosterone conversion, going on then off, affected me in some way) aged 19 for three months and developed blepharitis/dry eyes (i believe related to hormones) and then quit. I was then left with problems and had subclinical hypothyroidism for a few years which suddenly became really bad and I had no choice but to go on meds. But I was totally healthy before 19. My other hormones were also not in range when I went on NDT, so I feel like maybe now, with the other hormones in the ranges, I stand a chance of getting the thyroid to work normally.

I don't think NDT is right for me as I don't have a conversion problem, but I really am guessing. I don't know what would happen if I tried to taper off the NDT. My dry eyes gets worse when I lower my dose and I get cold.

I don't think my dry eyes/blepharitis is a good barometer, still not right when I was on too high a dose, so they don't require the level of T3 the rest of my body requires, I had been using them as a guide, but I think this is a mistake and my heart rate and blood pressure would be a better guide.

The fact that you were perfectly healthy before 19 doesn't prove anything. Hypothyroidism can come on at any age, and for a variety of reasons. You may think you have a chance of getting your thyroid to work normally because your other hormone are in-range (not the same as optimal!) but how do you propose to do it?

It's not just people with a conversion problem that take NDT, anybody can take it. There was a time when it was the only thyroid hormone replacement existing.

Your dry eyes might not be a barometer, I don't know, but feeling cold certainly is.

But, you could speculate forever about this. The only way to know for sure is to stop taking your NDT. Not that I'm encouraging you to do so, not by any means. But, you're never going to find out otherwise, are you?

Thanks greygoose, I agree.

How long would it take for it to maybe pick up? 10 days or a month?

I was thinking of tapering down and maybe taking selenium, iodine and tyrosine while I try and come off.

I just don't know if i can risk it at the moment as I have lots of final interview rounds coming up. So I am leaning towards waiting and trying in 2 weeks. I am not sure I can face seeing a new doctor and getting Levo prescribed and changing the whole schedule, when I am probably stabilish on 2.5 grains.

I can't find much information on people quitting, I imagine it wouldn't be pleasant for 2-3 weeks?

I have no idea how long it would take for the thyroid to kick back in. But, I would recommend testing after the usual 6 weeks. But, whatever you do, don't take iodine! That would probably scupper any chances your thyroid had of working again. Just leave it alone and see what it does. If it doesn't start working again, you could try testing iodine, to see if you're low, but after all these years on NDT, I very much doubt you will be, because iodine is recycled in the body, and your thyroid hasn't had to use any whilst you've been on NDT.

Hi greygoose, Ive only been on NDT only for about 6 months. I dropped my thyroid dose from 3 grains straight to 2, and am about 5 days in. I am very hot and heart rate changing, which I'm guessing maybe adrenals, I'm kind of regretting this experiment, but going to see it out and try and measure my thyroid in about 9 days.

That was rather a big drop in one go. 1/4 grain every two weeks would be far easier on your body.

Got my results T3 4.22 (2.5-3.9), T4 6.3 (6.1-11.2) TSH 0.031 ??, felt so lethargic/depressed the last 2 weeks, especially in the morning. I dropped from 3 grains to 2, and this is after 2 weeks. I took 1.75 grains in the morning and .25 about 4pm. These results were taken at 5:50pm after my normal 1.75 grain am and no doses after.. I don't know what's going on, as I am over the range for T3 and nearly under the range T4, I think I have been overmedicated the last 5 months as I have been dosing 3 grains, and I don't have a conversion problem. I don't know if my thyroid has picked up.

Two weeks was too soon to get an accurate reading, because some of the T4 will still be in your system.

You didn't give a result for your T4, there, but it would be normal for it to be low when taking NDT. But, your really don't know if you have a conversion problem, because you've never been on T4 only.

The only way to know if your thyroid has 'picked up', is to stop the NDT altogether. But, if you're going to do that, reduce slowly.

Hi greygoose, thanks for the speedy reply, sorry, my T4 was 6.3 (6.1-11.2), so pretty much at the bottom, I don't understand as surely T3 goes out the system, so dropping from 3 to 2 how can I be above the range T3 and nearly below the range T4?

I'm thinking that NDT is the wrong medication for me, or is it normal to be below range T4 when taking NDT. The last 2 weeks on 2 grains, I felt so lethargic/depressed, fatigued. I don't know how that can be.

I think I don't have a conversion problem, and I should be on thyroxine.

I'm thinking of trying thyroxine and changing over, as I've never been comfortable on NDT, I have high blood pressure , and heart palpitations on it. I suspect for large parts of the day I have been above the range significantly the last few months on 3 grains.

If I go low, I have so little energy, If my T3 is above the range and T4 very low and TSH suppressed, is that a good sign to try and change over to thyroxine and then try and come off slowly? as I think my body is more normal now, after my crash in December.

Well, why don't you go over to thyroxine and try it?

FT4 can be pretty low when taking NDT or T3. But it is strange that your FT3 is so high on only two grains. Do you have Hashi's?

Nope, well I might do now, is that the thyroid disease, I had an antibody test ages ago and the NHS didn't pick up on anything. But I doubt it unless prolonged medication can cause it.

Yes I really don't understand how my thyroid can be suppressed and go down a whole grain and be above range, when it was below on 3. I didn't feel good mentally at all on 2, and had very little energy.

Ok I wanted to try and quit altogether, but felt too lethargic the last 2 weeks, and I can't afford to be like that at the moment. Say if I try and switch to thyroxine, from 2.5 grains NDT, should it go something like

2.5 grains NDT --> 1.5 grains NDT 60mg T4

wait 4 weeks

--> .5 grains NDT 120mg T4

then try and taper off thyroxine until TSH is 1?

Is standard T4 - thyroxine sodium, abbot brand? or is Levothyroxine sodium (eltroxin)? Do you know what the NHS prescribes?

Just because the NHS didn't pick up on something, doesn't mean it doesn't exist!

1 grain NDT is about 60 mcg, not mg. 38 mcg T4 + 9 mcg T3. If you take T3 to be 3 times as 'strong' as T4, that works out at 38 + 27, so a little more than 60 mcg. But, it varies from person to person. Try 60 mcg and see how it goes.

I have no idea what brand the NHS prescribes, I don't live in the UK.

Ok thank you very much. Do you know about GSK and aspen brands of thyroxine? As I may order some just to have the option, and then go to my GP when I get back to the UK.

No, I'm afraid I've never heard of them.

Hey greygoose, I was on NDT and having problems of being overstimulated, I have changed over from 3 grains NDT to 1-1.5 grain NDT and 50-100mcg T4, and feeling a lot better.

My plan is still to try and change over completely to T4 and then maybe in the future try and wean off meds altogether. I am not sure what doses I should be aiming for? , is 160mcg T4 equivalent to 2.5 grains NDT?

One grain of NDT contains 38 mcg T4 and 9 mcg T3, so 2.5 grains contains 95 mcg straight T4. Trying to work out how much T4 is equivalent to 27 mcg T3 is just a guessing game. It very much depends on how well you convert. And we don't know how well you convert. We could split the difference and say 27 x 3 = 81, in which case 2.5 grains NDT would equal 176 mcg T4. But, we could be wrong. All you can do is try it and see.

What makes you think you would be able to come of thyroid hormone replacement in the future? It's a very rare thing to be able to do - if ever. And I doubt that.

Ok, I am trying 1 grain in the A.M and 100mg T4 in the P.M, I do take my NDT when I take other things like caffeine/theanine. Should I try and have breaks between the meds.

I have had less heart issues, but find I need more sleep and am tired in the morning, more like my peers. And more depressed. But maybe it is a transition period.

Before I could get up at 5am every day and go straight into work.

NDT has to be taken exactly like levo : empty stomach, one hour before eating, etc.

I cannot see any advantage to taking NDT in the morning, and levo in the afternoon. You might just as well take them all together. It would make life easier for you. :)

Thanks, my current dose of T4 and NDT has been way better for me than with just NDT, I am not having heart issues. I feel like I have come down a bit from when I was at 3 grains NDT.

If I want to try and slowly get off this dose in the future would you keep the NDT and try reducing the T4 or the other way round.

Well, it depends why you wanted to come off this dose. Why would you?

I am on 1 grain in the A.M and 100mg T4 in the P.M, I would like to come off as I think it is easier to be off medication, and healthier in the long run, If my body can adapt to being off medication, which I believe it may be able to.

Well, I think you might be in for a nasty surprise, there. If you were diagnosed hypo, then you are more than likely hypo - doctors don't make that sort of mistake and thyroids don't repair themselves - nor does diet or anything else repair them. Your body will be in shock and is very unlikely to adapt to being without thyroid hormone.

When you become hypo, it happens very, very slowly. The body adapts to a certain extent, but the symptoms increase over time, and you feel more and more sick. I very much doubt you would have the patience to reduce your dose at that snail's pace - it would be super human! Especially with the symptoms coming back, because they would not doubt appear a lot faster than they did the first time.

So, why exactly do you think it will be easier and healthier to be off thyroid medication? You do know you can't live without thyroid hormone, don't you? Doesn't sound very easy or healthy to me.


Yep, I tried coming off and went too low again, I felt stable on 0.8 grain and 88mg T4, but tried to cut that even further.

I want to come off as I outlined before: I never had a thyroid issue, just my hormones were generally out of whack, and the thyroid crashed at one point, which is why the doctor prescribed me. I think it was a mistake and my body would have normalised or not needed as much thyroid.

I was on 3- 3.5 grains, and now I am on 0.8 grain and 88mg T4 which I feel a lot better on and is surely lower,?

So I am hoping to keep reducing it.

I don't know what would be easier to try and reduce—the NDT or the T4.

I tried the last 2 weeks to go to 0.5 grain 0.5 T4, but feel very sluggish.

I have just read that it isn't the T3 in the NDT that suppresses the thyroid just the overall dose, so my thyroid should be less suppressed reducing T4. I was worried that if I reduce my T4 dosage my body won't feel less suppressed due to the same artificial T3 levels.

I think I am going to try and stick with 0.8-1 grain NDT and keep trying to reduce the T4 as I think it would be easier to stay on NDT to have the little kick of T3. Say reduce the T4 every couple of weeks.

I'm sorry, but I have to say, I think you're kidding yourself if you think you can come off thyroid hormone replacement completely. You have no grounds for thinking you don't have a thyroid problem, and thyroids don't recover, they just don't. You say somewhere above that before going up to 6, your TSH was always 3.3. Well, 3.3 is hypo. And the fact that you are having trouble reducing your dose shows that you need it. If you didn't need it, you wouldn't have any trouble coming off it because your thyroid would automatically take up the slack. Sorry. :(


Too much of any thyroid hormones can cause problems. But T3 is the only Active thyroid hormone needed in all of our T3 receptor cells. T4 is an inactive hormone and has to convert to T3. We cannot survive without T3. We can without T4.

Why would you want to take thyroid hormone replacements if you've never been diagnosed.

Do you think that could be causing the problems you are having at present.

Palpitations can be caused by too little thyroid hormones in our body. Or too much.

in reply to shaws

My hormones crashed in October 2017, my TSH was 6 and T4 below range for months, before that I just had a high TSH (about 3.2) and felt slightly unwell. This was all after taking finasteride for three months (2015), I am young, and had no health issues before. But maybe it is hoping for too much.

I think the palpitations are a sign something really isn't at the right level, I don't really notice my heart rate in the day.

I take 2 grains in the morning and 1 grain at 3pm of thyroid-S. I'm thinking of going to 1.75 grains morning and pushing the latter dosage to later to see if that will help. My blood test with 3 grains was in range, but it was just before my beefy 2 grain dose, so probably a lower concentration than I normally have?

If you had a pituitary or hypothalamus signalling problem and you still need testosterone therapy because hormones are low, I doubt that you'll be able to produce thyroid hormones either. Rather than guessing, why don't you get a blood test done and post results for advice

Well testosterone does suppress my natural production to a more irrecoverable level even if I was fine beforehand. Yes maybe it is dreaming, I just feel the rest of my body is in better shape so maybe my body would be able to find homeostasis, I am not sure the exact problem, but I guess it is a signalling problem induced by hormone altering drugs at 19.

I wasn't producing T4, before I went on.

Now I think I need to switch off NDT as it does feel very unnatural and dangerous. I have high T3 and low T4 and feel overstimulated at points in the day, my heart rate goes to such a frightening pace every evening that I am a bit scared, but really just want to put the health worries away and focus on real life. I am thinking of maybe trying to see Dr. Bernard willis in 5 months if I am not managing, to switch off NDT or maybe taper off completely.

My latest blood tests with 3 grains

TSH 0.02

FT4 13.1 (12-22)

FT3 5.4 (3.1 - 6.8)

and when I was on 3.25-5 grains


17.3 (12-22)

7.5 (3.1-6.8)

These tests were taken 24 hours after my main dose, so I feel like they are underestimates for the T3.

My T4 is very low and my T3 is probably 5-7 in the 24 hour period, I'm not sure if my dose is too high or its my dosing schedule causing the heart palpitations?

Your current results look "usual" for someone on NDT. You could try dropping by 1/4 grain, but your free T3 would probably fall and it isn't high now. Your previous results did look overmedicated as free T3 was over range. Palpitations can be caused by many things - both under and overmedication and not just thyroid meds. In most cases they are not life threatening - just annoying. Why not ask for a referral to cardiology if they are really bothering you?


You can stop one thyroid hormone and switch to another approx at the same level.

I had the severest of palpitations on levothyroxine i.e. very late at night or early a.m. I didn't realise this until I tried several alternatives.

There are two reason we can have palpitations:-

1. We are sensitive to fillers/binders in some thyroid hormones replacements.

2. We take too much but this isn't usually a problem if we gradually increase dose by a small dose being added every two weeks, keeping an eye on temp/pulse and if either goes too high, drop back to previous dose.

3. Too low a dose. i.e. an optimum dose is when we feel well with no symptoms.

in reply to shaws

Thanks shaws, My FT3 comes back a good level 24 hours after my main dose, so I don;t think I am too low, and I guess that means I am too high even though my T4 is low.

That's interesting about the fillers, I don't get the palpitations midday, after my two grain dose?

Yes I have found it really hard to pinpoint things as I am on testosterone replacement therapy which comes with estrogen control and hcg, which have their own sets of problems.

I have kept those completely constant and know its the thyroid now, specifically T3, as I lowered my dose and the palpitations were not there.


Palpitations can be caused by meds but also high cortisol too.

You should be monitoring your temps. If they are over 36.50 on 4 average readings then yes you’re on too much.

If they vary significantly your adrenals are out. Quick and easy test. Look up Dr Lowe from New Zealand- a true legend who only did one blood test.

Good luck

in reply to Howard39

Hi Howard39,

I tried the temp monitoring but found the digital thermometer I had too inaccurate, even though I bought a good one on amazon.

Maybe it is my adrenals, it definitely happens in the evening without fail.

Thanks for the advice, I see Dr Lowe talked about a lot.

in reply to biowarrior


Mine are basal ones which are pretty cheap and last a while. They are accurate.

in reply to Howard39

I think you'll find Dr John Lowe was American. :)

in reply to greygoose


Yes he was. Thanks for the reminder. Just the cows are in New Zealand 🤐

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