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Thyroid UK
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Where to buy NDT, how to come off T3/T4 and dosage equivalencies

Hi All,

I have been persevering on a T3/T4 combo for quite a while now and am still so so tired and gaining weight. I thought trying NDT may be my only option left but really don't know anything about it.

I currently buy my own T3 as my GP and Primary Care Trust refuse to prescribe it, so I am fully prepared to buy NDT too.

My current dosage is T4 125mcg and 25mcg. On this dosage my T3 and T4 are still below range according to my recent bloods.

Please could anyone offer any advice as to where to buy (obviously PM me only), how to swap to NDT and how much I would need to take.

As ever, your advice is invaluable and hugely appreciated.

C xxx

6 Replies


If FT4 and FT3 are below range you are under medicated. Your current dose/s are equivalent to 3 grains (180-195mg) NDT but you will require more to raise FT3. You can switch straight over as you are already used to taking T3. Most people on T4+T3 or NDT feel well when FT3 is towards, or in, the top third of range.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.


Thank you so much Clutter. I'm really nervous about changing over but I really feel after struggling on and off for three years, I have to change. Is NDT better taken in split doses or all at once in the morning?


I take mine in split doses. (Though I have only been on it for 5 weeks) But I have noticed that if I split the dose and take it roughly the same time each day, it has a better effect. I wake up at 5 am and take one dose and then take the other at around 12/1 pm.

1 like


Why not increase your T3 dose and see whether you feel better when FT3 is optimal rather than switch to NDT?

I don't take NDT but I think because it has T3 it will be better to take it divided into 2 doses.



I have asked my endo if I can have an increase in t3 but he has told me to increase my t4 instead 😢 I feel like I'm banging my head against a brick wall. I used to run and do triathlon, now it takes me all my energy to do a day at work and the school run. It's awful.


Thank you so much for this, I will look into it :-)


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