Thyroid UK
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NDT & symptoms

Hi I have posted before but wanted to update as I changed over from 100 mcg Levo daily to 1 Grain NDT on Monday started getting non stop headaches so cut down after 4 days to 3/4 grain still got headache this morning Sat 4/6 😢 Was thinking on not taking any today and start taking 1/2 grain from tomorrow can I be advised if this is the correct thing to do to get these horrid headaches to subside

9 Replies

100mcg of levo is approx equal to 1 gr of NDT.

It's a bit of a predicament. Sometimes we can have a sensitivity to the fillers/binders in a product and I've read that taking an anti-histamine 1 hour before taking tablet and if you don't have the same reaction you'd have to switch to another NDT. It is trial and error at times.

Also if we take a dose of hormones which is too 'low' that can also give us problems and additional unpleasant symptoms.

I had to try several NDTs myself.

Maybe try an anti-histamine first - it might prove you have a sensitivity if a headache doesn't develop.

I only know of two NDTs which are hypo-allergenic and that's Nature Throid and WP by RLC labs.

I know, too, how disappointed you will feel at present.

I assume your pulse and temp remained steady and it was the headache which was the problem?

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I'm on Nature Throid so that's good news ! My temp was 35.8 this morning which is an improvement on 34.5 my pulse is normal but my blood pressure is slightly high at 148/86. I also have raised cholesterol all signs of hyperthyroid symptoms not being addressed. Do you think I should skip taking it today and start in 1/2 grain tomorrow as was thinking maybe I have too much T4 in my system ! It's just these constant headaches that are worrying me


It has been said that we can do a straight switch-over from one to another but it might not always work that way for some of us. We are all different and also our doses are not identical either.

I shall give you a couple of links and the first is regarding how we used to be treated (no blood tests then) and we were given sufficient until our symptoms resolved.

Yes, you can start on half-grain as you suggested and then you can every two weeks do another increase and so on until you feel better some raise by 1/2gr and others 1/4. I think if you feel you are nearing an optimum go up by 1/4 as it is easier to drop back by 1/4. Always take note of temp/pulse as they are good guidelines i.e. too much - pulse will be too fast so you go back to previous dose. We might feel very hot but temp might not have changed much.

Raised cholesterol is a symptom of hypothyroidism, due to our metabolism being low probably for a long time before being diagnosed. Hopefully your blood pressure will also fall into normal line as levo can also interfere with b.p.

Blood tests will also not correlate with the ones introduced along with levo as we will have T3 in the NDT which will reduce.

Keep in mind I'm not medically qualified but have just run the gauntlet that many appear to do so on this forum and am fortunate to feel well now.

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You will have considerably less T4 in your system on 1 grain NDT than when you were taking 100mcg Levothyroxine. It may be the T3 in NDT which is causing your headache. Some members do report experiencing headaches when they first use T3 but it usually passes within 10-14 days if you can ride it out. Try splitting dose and take half grain on waking and a second half grain dose at bedtime.

If you reduce to 1/2 grain the headache may resolve but you are likely to become under medicated and hypothyroid.

Elevated cholesterol is common when undermedicated and prior to blood tests high cholesterol was a clinical sign of hypothyroidism.


Should I just continue on 1 grain then ? Never took it this morning but will take it now



If you have done a straight swop from levo. to NDT it can be that the T3 in the NDT can be a bit of a shock to the system, this is why it is best to start on a low dose (say 1/2 grain) then increase very 2 to 3 three weeks by 1/2 grain if you are tolerating it well, or 1/4 grain if you are sensitive to it.

You will still have some T4 in your system from the levo. for a few weeks, so as you are increasing the NDT the T4 in the levo. will be decreasing.


I had awful headaches when I first went onto Armour and they return with every increase in dose but eventually subside. I also started on 1 grain. I get headaches even with a quarter grain increase. In my experience it's best to keep the dose stable and tough it out if you can (I took time off work). The headaches eventually subsided. It takes me weeks and weeks (6-8) to get the full benefits from a dose increase - a lot longer than everyone else seems to experience. I have found that sometimes it's possible to get rid of the headache with a strong cup of caffeinated coffee - I'm usually caffeine free. Painkillers seem to be ineffective however I don't find that T3 causes headaches, just Armour but I haven't tried other NDT. I was very worried about my headaches too, but now they've gone I can say that they didn't seem to cause any other problems just pain!

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Yes no other symptoms but glad for all the advice you have given me, so I will solder on as I don't want to go back on Levo again!! What dose have you levelled out at and how much Levo were you on before you started taking NDT ?


I used to take about 250mg of thyroxine, and then about 50mcg thyroxine, with up to 40mcg T3. Currently on 1.75 grains with 20mcg T3. I find it very hard to get stable and have to make seasonal changes. My TSH is always suppressed whatever I take so that also makes it difficult to control and adjust. I always have to rely on symptoms and signs. I'm still a work in progress :)


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