Thyroid UK
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NDT advice please

As I feel worse with each increase of synthetics t3 and t4 I am looking to try this.

I am currently taking 125 Levo and 20 mcg t3.

What would be the equivalent to this? There are so many different strengths , What would it be best to order?

A request for a named patient trial has been refused by my doctor who professed never to have heard of it .



10 Replies

The approx is 1 grain of NDT is between 75-100mcg of levo. 20mcg of T3 is approx to 60mcg of levo or 1/2 grain of NDT. So maybe 1 1/2 gr to start and then work up an increase every 2 weeks till you feel better. Take your temp/pulse before you begin and keep a note of them so if your temp/pulse begins to rise too much you can drop back a dose.

"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 shaws .



As someone who switched, unsupervised, I am always worried when people decide to switch to NDT. Why because I realise now that I took a great risk, and was lucky to get away with it.

You can calculate the approximate equivalent of NDT, but you cannot predict your response. So please, no matter how desperate you are, go slowly. Replace around a quarter of your current synthetics and sit back and see how it goes for at least two weeks. If you have had no adverse reaction try going to half and half. When you get to three quartets give it at least a month and get tested.

I switched far too rapidly, and went hyper. That is because, I know now, I don't convert levo, so my quite high dose did nothing for me. I didn't need the NDT equivalent, because that actually has an effect.

In your case I wonder why you feel worse?. There are a myriad possible reasons. In my case, although I knew nothing about adrenals, mine were already disturbed as a result of being denied thyroid treatment for many years. There is no doubt in my mind that my hasty switch stressed my system even further. I am still paying for that.

Going slow will give you the chance to watch the changes and fine tune your dosage. I don't regret switching, and wouldn't dream of suggesting you shouldn't try doing so too. Just proceed with caution with this powerful medicine.


So informative Ruthi , I may be picking your brain in the future lol

Thank you



PP, 2.75 grains NDT contains 104.5mcg T4 and 24.75mcg T3 equivalent to 178.75mcg T4. You're currently taking the equivalent of 185mcg T4. Most economical way would be to buy 2 grain and 1 grain tablets and cut the 1 grain tablets in halves and quarters.

Med students are only taught about Levothyroxine so it's very likely your GP isn't aware of the acronym NDT but he may have heard of Armour. Some doctors think NDT or Armour is a herbal thyroid supplement :)


My GP refuses to prescribe any T3. I have been on Levo for 13 years with worsening symptoms as well as infertility (undiagnosed). In facet the only time I ever got pregnant was when I ditched my T4 in disgust. The GP said it was a 'happy coincidence ' and nothing to do with stopping Levo...still unsure but 4 years later still no conception.

Where do you buy T3? It seems my only option is to substitute some of my dosage to that. Please can someone tell me the cost and where/ what brand is reliable. Thanks.



I persuaded the Endo to give me a trial of t3 .

Unfortunately it hasn't had the good effects that some people have.

Someone will probably pm you as to where to buy it.

Regards Pp


Thanks as always Clutter

I bet if there was a thyroid sufferer in his family he would know all about it.



The trick is to start on a low dose and build it up over a couple of months. Personally I stopped taking levo for two weeks before starting NDT as levo has a life of up to 7 weeks! If you are taking T3 as well I would say carry on with the T3 for a little while not dump it like the levo! You can always reduce if you think you need to but please do not just swap your dosage and think everything will be OK because it won't. I'm sure doctors tell you to so they can say that you tried it and it does't work! Take your healthinto your own hands, its safer there! Most doctors won't prescribe NDT because it is expensive, not because it doesn't work.


Thank you Glynisrose

It can't be as expensive as the t3 I'm taking.

I will take all comments on board and proceed with caution.



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