Thyroid UK
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Changed to ndt

Hi could anyone help with any idea how long you should wait to increase your ndt + how long approx you start feeling better. I was on 100 mg of levo but wasn't feeling better + GP wasn't interested as my bloods were OK he said. I've had to self medicate + bought nature thyroid 65 grain. I started with half + then 3/4  3 days ago but still not feeling any better. I would be so grateful if someone could help giving me any information you can as i m not sure what to do next. Thanks in advance for your help

7 Replies

The standard advice is to start with half a grain, and increase by half a grain every fortnight until you reach a dose that allieves symptoms. But those who've previously been on levo can usually start on 1 grain (I did) and raise by half a grain from there after a fortnight.  Most people end up on 2-3 grains of levo (some less, some considerably more).

Are you experiencing hypo symptoms? I think I'd raise to a grain a day now, but don't be tempted to raise it more until the fortnight has passed - it takes a while for the levels of T3 to build up in your system and it's much easier to raise slowly than to go too fast, crash and have to start all over again.


Bear in mind too that sometimes other things need to be addressed. You may be low in ferritin, Vit D or Vit B12, all of which need to be optimised to get the best bang for your buck from thyroid hormones.  If you find that Nature Throid isn't helping as much as you'd hoped, it would be worth getting some private blood tests done to see what your vitamin and mineral levels are.

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If you were already on levothyroxine at 100mcg, you could have started on 1 gr of NDT straight away and after two weeks you increase by 1/4 or half gr until you feel an improvement. My preference is increasing by 1/4 as it's easier to drop back if your pulse/temp rises too much.

Your dose at present is lower than your levo dose but it's the effect of the dose which is the priority. Hopefully you'll feel better soon.

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Not sure why but when I started ndt with 1 grain (split in 2) I crash after only 5 days. I was not able to keep the 1gr dose two weeks. I was on 125 mcg levo.


I was on 100 mcg levo, started on a grain of ndt (naturethroid) and upped it to 1.5 grains after a month (took a while to get bloods back). That seemed about right for me but we're all a bit different.

Sounds like you feel pants because you're under medicated although the levo should have persisted in your system for a while after you stopped so this may have compensated, which may mean that you start to feel worse before you get better....


Hi Alfino,

I think you need 1 1/2 grains to be the equivalent of 100mcg of levo, if that's a good dose for you.

1 grain of my WP is 38mcg of T4 & 9mcg of T3, so is approximately a 66mcg equivalent of levo, as T3 is supposed to be around a third stronger than T4. Individual brands differ in content & strength,



I stopped levo for 2 weeks before starting NDT.  I started on 1/4 grain and built it up over a few weeks.  Could not believe how much better I felt.


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