Thyroid UK
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Has anyone started on NDT whilst iron/ferritin is rock bottom?

Hi - I'm going through the preparations stages (loads of relevant blood testing) before I take the leap to go and see someone privately to get NDT prescribed. I've been on T4 only for over 2 years and I still have some hypo symptoms. I have ongoing problems with iron deficiency - my ferritin is currently 12 and the most it has ever been is 25. I really want to start using NDT but I worry that this is going to be thwarted by low iron as I know it affects how it will be used in the body.

Does anyone have any advice or experience with transitioning from T4 to NDT with low iron and ferritin?

Thanks very much in advance.


4 Replies

BlueMallers, Low ferritin/iron won't prevent you using NDT any more than it prevents you using Levothyroxine but it can make it difficult for some people to tolerate dose increases of either.


thanks for responding Clutter. Yes I see your point - I'm on 175mcg of levo and I feel crappy. I might as well try NDT. My blood pressure has gone up to 122/88 as well and my cholesterol has risen whilst being on T4. I've been reading on STTM site that eventually on T4 these things will happen and it has so I really want to try NDT.

Thanks again.



BM, 175mcg T4 is equivalent to 2.75 grains NDT. It's recommended you transition gradually to see how you tolerate T3.

Week 1 reduce T4 by 50mcg and add 0.5 grain.

Week 3 reduce T4 by 50mcg and increase to 1 grain.

Week 5 reduce T4 by 50mcg and increase to 1.5 grains.

Week 7 stop T4 and increase to 2 grains.

Week 9 Increase to 2.5 grains

Week 11 Increase to 2.75 grains, hold for 6 weeks and have a thyroid test, including FT3, before increasing further.


Thanks so much this is really helpful. It's very nerve-wracking facing coming off T4 onto NDT - it takes me back to going onto T4 in the first place which I'm sure a lot of people can relate to. I'll keep the forum posted on how I get on - over the coming months.


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