Thyroid UK
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Changing to NDT

My prescription for T3 has been withdrawn by the NHS and my GP has suggested that I go on the internet to purchase my thyroid medication. Now seems a good time to convert to using NDT, but I'm unsure of the dosage. Currently, I'm on 75mg of Levothyroxine and 10mg of Liothyronine. Can anyone help me to find a way to convert this to an NDT equivalent?

6 Replies

I had assumed that T3 was being stopped by instructions from the BTA altogether ,but I've had confirmation from Lyn Mynott of TUK and this is her reponse to me:-

"Hi Shaws, It's not the BTA who have ordered T3 to be withdrawn. In fact, their new guidelines state that patients already on T3 should not have it withdrawn.

I believe it's the fault of PrescQIPP sending out their bulletin showing how much could be saved that set this particular ball rolling. :"

1 grain of NDT is equivalent to around 100mcg of levo.

1 like

Hi shaws, thanks.

I agree that the guidelines are being used to suit by GPs. Do you have a link to the new BTA guidelines? I can then present it to my GP and ask again why my prescription is being stopped.

Thanks again.


This may be the one (even though their preference is levo only):-



Thiroyd, for example, contains 35mcg T4 and 8.31mcg T3 per grain (which is a tablet). So, two grains might be right. Other options of porcine NDT contain slightly more T4 and T3.

Your GP may be happier for you to not exceed your current dose of T3, in which case one grain of NDT plus 50 mcg of levothyroxine should be OK.

Although your body is used to receiving exogenous T3, it's usually recommended to start with a low dose of NDT, monitor heart rate, temperature and symptoms of over-substitution, and increase the dose gradually, every fortnight.

I hope your GP becomes a real asset in your journey to health, and can help others, despite the current strictures.

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I would write to your GP (cc your MP) and tell your GP that the CCG does not have the authority to tell GPs what not to prescribe and you believe your GP is in breach of GMS contract by withdrawing treatment you have been told you need. Say you have been well on Liothyronine and wish to continue taking it. Attach the BTA guidance for patients and GPs.

The BTA issued guidance that patients doing well on T3 should not have their prescriptions withdrawn. See FAQS for patients and GPs in british-thyroid-association...

CCGs do not have the authority to tell GPs what not to prescribe. Individual GPs, not CCGs, could be found in breach of the General Medical Services contract if they do not prescribe treatment patients have been told "they need".

The GPC has warned that GPs would be in breach of the GMS contract and could get into legal trouble by following the orders and refusing to prescribe patients treatments they have told them they need.

If you still wish to switch to NDT then 1.5 to 1.75 grains NDT is equivalent to 75mcg Levothyroxine and 10mcg T3. You are used to taking T3 so there is no need to titrate NDT.



Please complete the NHS England Survey re deprescribing Liothyronine.

Please also sign the petition requesting better thyroid diagnosis, testing and treatment.


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