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Thyroid UK
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Any advice for someone new to taking Thyroid-s and getting dreadful stomach cramps!

I have recently self-diagnosed under active thyroid after two and half years of symptoms. I started taking Thyroid-s slowly upping the dose by half a grain every two weeks. Feeling wonderful on 2 grains and symptoms all starting to disappear and went up to two and half grains and within a week I had started to develop diarrhoea and horrible stomach cramps! I was taking the NDT on an empty stomach and I already have colitis.

I have come off the NDT until the stomach recovers.

Does anyone know what this reaction is? I have seen that people on synthetic hormone also get these symptoms, and it certainly feels more like an overdose rather than a reaction to fillers.

Thanks Jonathan

34 Replies

I take Metavive and was advised that it was better for the stomach to take it with meals. It works for me; I take it at the start of my meals. I know most advice on here is to take it away from food etc, but you may find that it suits you better. You may need a little extra, but dosage is by trial anyway.

2 weeks between raises is rather fast. You can't rush your body into these changes. Maybe 4 to 6 weeks between raises would give your system more time to readjust.

All the best.


Diarrohea is a symptom of over medication. It sounds like you went too high with your dose and should go back to the 2 grains as you felt so well on that dose.

The other thing to bear in mind is that you have increased your dose every two weeks -normally its 6-8 weeks before a dose is increased to allow the body to get the full effects. Increasing fast ie every two weeks means that you are more likely to end up over medicating.


Isn’t that for levothyroxine/T4 rather than NDT?


TSH110 -I dont really understand your comment that its for levo rather than ndt?


waveylines I used the thyroid Patient Advocy guidelines:

1/4 grain 7 days

1/2 grain 4-5wks

1 grain 3wks

And additional 1/2 grain increases every 3-4 weeks until dosage is optimised. Dose was split am and pm.

Nothing about 6-8 weeks there and it worked fine for me.

Mind you that is not to say Increases in dose every two weeks is a sensible way to go, I agree it is far too rapid.

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Gllad that worked for you TSH110. 😊😊 Was that for transferring across from levo to a ndt?

I feel I can only say what the nhs doctors would say which is 6-8weeks incremental increases when introducing thyroid meds whether levo, liothyroxine or ndt. Thats what my nhs endocrinologist recommended -one of the rare ones who does specialise in thyroid med treatment!!

Completely get that everyone is different and we all have to find our own way but key is to not increase too quickly.....

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waveylines it May have been ok because I was swapping from Levo so already had been optimised on that (but continued to feel unwell with persistent. Hypo symptoms). What I did was add in the NDT whilst reducing the Levo rather than start with just NDT. Those are still the TPA recommendations for dosing whichever you do. Obviously there are provisos that you only increase if everything goes well and cut back if the optimal level is exceeded. I only had to go up to 1.25 and was very cautious.

I can’t see any rationale for the timing on the TPA guidelines perhaps it was the method used by doctors when NDT was the only thyroid medicine and blood tests did not exist and I presume half lives of T4 and T3 had not been elucidated


Transferring across is very different to introducing a thyroid med for the first time. Although technically you can just start taking the equivalent I built the ndt up towards my equivalent levo dose gradually but used a faster protocol slowing down increases as I approached the equivalent dose.

Bit different when introducing thyroid medication for the first time as the whole body has been slowed down by the lack of so it also needs to be woken up alowly & careful. This is what Dr Skinner told me at the time of starting treatment......may he rest in peace.

I totally agree with you that one should listen carefully to ones body as we are all different. Best to be cautious as you say. 😊😊

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waveylines How wonderful you knew Dr Skinner a very remarkable man and a hero of mine!

I had awful heart pains for years due to undiagnosed hypo I presume. I had minimal doses of Levo and a long slow titration to optimisation - hellish but the heart pains were even worse on Levo even after 2 years with a very low TSH, so was very afraid of starting NDT and overcooking it. I had to pull back a bit at the half grain stage as I think the T3 really overwhelmed my system. But even on 1/4 grain and 100mcg Levo I started to feel huge improvements - very rapidly like in a few days - the main of which was feeling like I was being put back together again and properly integrated not like a two dimensional non entity of a shadow I seemed to have become just like putting the last piece in a jigsaw puzzle and seeing the complete picture - it was fantastic! So I kept going and the improvements continued I got to 1.25 grains and felt completely normal again. The heart pains reduced but have never gone right away. I have had 3 good years on ThyroidS but this last 6 months have not been feeling as good but not sure why . Still a lot better than I felt in levothyroxine. I have discovered I have that DIO2 business and have a combination that causes decreased T4 to T3 conversion which would explain the pretty miraculous effect the NDT had even in small quantities.


TSH110 so glad you took charge and found a way forward that works for you. Maybe you need a bit more ndt? has there been a change a further drop in output from your thyroid? I always take more in winter...

Dr Skinner was a wonderful man. Literally saved my life! Id been left on 50mcg of levo for a whole year after diagnosis and unbeknown to me had a very high TSH and crippling low thyroid hormones. The doctors had not even told me! Negilgence!! I could barely walk. Dr Skinner, charming, witty clever perceptive doctor sorted it. He saved me. And from that time on I have never relied on the GPs to sort me. I check everything!! I read loads.

Knowledge is power!! 😊😊


waveylines I don't think mine works as I was told it was tiny and all shrivelled and very unlikely to have any function at all by the endo after an ultrasound exam. If I increase the NDT I seem to become overmedicated. I do wonder if I need a little more T3 with it but have not bought any because it is so expensive. I never needed to take more in winter for those 3 years. I work outside in a physical job so at least get more daylight than many. I am a bit concerned that I have blood pressure after having perfect results all my life and wonder if it might have anything to do with it. My heart has never really recovered from all those decades of being hypothyroid with no treatment. I have no faith in doctors where thyroid health is concerned they couldn;t even diagnose me when I told them what it was and that it was in the family then they put you on medication that they insist works for everyone and label you a depressive who imagines symptoms if you still feel unwell. Then you take NDT and discover they are fakes telling you lies, and that it is everything to do with undermedication and has nothing whatsoever to do with mental illness!

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All thyroid meds, really.


Angel_of_the_North i followed a different protocol details above which worked fine


I think it depends whether you are starting from scratch or just transferring across from levo. Some people seem to be much more sensitive, in a bad way, to thyroid hormones than others and take longer to adjust to a dose. Apart from the initial 1/4 grain, that's still leaving a month or so between increases, which seems sensible.

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Hi Jonathan

You will find a list of ingredients here:


And here’s a guide to getting the correct dose l that might be helpful:


Hope those help.

I tolerate it well


When I started on thyroid s i raised every two weeks until two grains and then waited for 4/6 weeks to 2.5 then another 4/6 weeks to 3 grains. I was losing weight on 3 grains and my FT3 was 8.2 and the upper range is 6.8. I was over medicated. I have never had any pains only frequent visits to the loo, hence the weight.

It does take time to sort out the correct dose as everyone is different. I started in June 2016 and am now well and balanced in December 2017.

I take NDT and T3 together now to feel well. I have no thyroid and no other problems.


When you say self diagnosed, presumably you did some blood tests first.

For full evaluation you ideally need TSH, FT4, FT3, TT4, TPO and TG antibodies, plus vitamin D, folate, ferritin and B12 tested

Add results and ranges and members can advise


Couldn’t agree more. Hopefully you have done all the blood tests mentioned above and not just looked at a ‘tick list’ of symptoms.

If that’s the case then post the various results along with their lab ranges.

I’d say it’s not a good idea to start treating or supplementing anything without having done blood tests.

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Slow Dragon Thanks

My blood test showed the following:

TSH 1.63

T4 77.3

Free T4 15.10

Free T3 4.37

Reverse T3 23.0

RT3 ratio 12.37

Anti-Thyroidperoxidase abs 10.2

Anti-Thyroglobulin Abs <10

Vit D 58 HbA1c-(IFCC) 37

Vit B12 312 hs-CRP 2.60

Serum Folate 30.6 Ferritin 94.6

Insulin 30.8 Magnesuim 0.99


Can you add the ranges on these results. All labs are different


Blue horizon ranges

TSH 1.63 (0.27 - 4.20)

T4 77.3 (64.5 - 142.0)

Free T4 15.10 (12.0 - 22.0)

Free T3 4.37 (3.1 - 6.8)

Reverse T3 23.0 (10 - 24)

RT3 ratio 12.37 Normal >15, Borderline 12-15, Low >12

Anti-Thyroidperoxidase abs 10.2 <34

Anti-Thyroglobulin Abs <10 <115

Vit D 58 Def < 25 Insuff 25-50

HbA1c-(IFCC) 37 20-42

Vit B12 312 Def <140 Insuff 140 - 250

hs-CRP 2.60 <5.0

Serum Folate 30.6 8.83 - 60.8

Ferritin 94.6 30-400

Insulin 30.8 0-88

Magnesuim 0.99 0.6 -1.0


Your vitamin D is on low side. Aim for around 100nmol. Make sure to retest twice yearly.

B12 might benefit from supplementing. Sublingual B12 lozenge and/or good vitamin B complex

TSH looked fine, possibly slightly low T4 and FT4. That could be due to low vitamins

Are these tests from before starting on thyroid hormones


Slow dragon

This test is from 4 months ago well before I started on the NDT. I have been supplementing like crazy for several months with a life extension powder mix, d-rybone and many vitimins and minerals. (I think the colitis and the effects on my intestine impedes the take up).

I will concentrate on B12 & vit D.


I had the same with Thyroid S and I too have Colitis. I stopped Thryoid S and changed to T3 and have no problems. Clemmie

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Thanks Clemmie. My Dr and Endocrinologist won't treat me and so T3 isn't available to me!


You can buy T3 as easily as NDT



Do you have a good company name?


You need to ask for PMs on a new post



Are you getting your T3 on the NHS?


No, it was prescribed privately and my GP said that he “wasn’t allowed” to prescribe it so I have to source it myself. But my surgery does do the blood tests for me. Clemmie


The advice about increasing dosage slowly is right on (or "spot on" as the case may be). The Functional Doctor that I see here in the states says that it takes 6 weeks for the dosage to be detected by blood tests.

The symptoms you describe do sound like over-dose. Be careful about going from 2.5 grains to 0 - you can make yourself really sick! (much worse than you have been) The advice on staying at 2 grains sounds good. I have made the mistake of going from one extreme on dosage to the other. You do not want to go there.

I agree with those that say you are over-dosing. Cut back, don't go to zero. Give yourself 6 weeks and decide how you feel. You may even feel the need to decrease!

Stay in touch - do let us know how you are doing. That's how we all learn.



Sounds like you overmedicated. Go back to 2 grains and have a thyroid blood test after six weeks to check levels.


Yes agree over medicated. I stopped Levo when I started on NDT and increased it slowly. Dont forget when you stop T4 you have a store of it in your body which keeps decreasing but your NDT is increasing so if all else is already in place eg optimal vitamins etc it should be a painless switchover. I was also told that once at 2 grains to stay steady then only increase in quarters but I still over shot my sweet spot. Thankfully I had an Endo appointment but he told me to drop back to 1.75 ( I was now up to 3 grains) and he was spot on! I've since gone up to 2 grains as I was put on medication that caused a degree of less absorption but been fine since. I do know my vitamin levels weren't optimal though before I started but I reversed my bad conversion first then went over to NDT.

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Why would they be any better than the NHS? You might end up paying for someone as bad as those you've already seen, who knows nothing about thyroid. If going to a doctor, I would get the list of doctors and endos with more of a clue from TUK


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