Thyroid UK
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Armour or Erfa?

Hi all. I recently went to a private endo because of the breathing issues I had been having.

He suggested I was taking too much Erfa, and to cut down and redo bloods after 6 weeks. He also suggested switching to Armour thyroid.

So, I cut down from 4 grains of erfa, to 3 and a half. Almost immediately I noticed my mood change. Weepy and depressed. Hardly sleeping. I went up a quarter of a grain and improved. Then my Armour arrived in the pharmacy. I took the same amount and my breathing is all over the place! Much worse then it ever was with Erfa! I got to the bottom of the road with the dogs and came home. Would have usually been out for an hour!

So....anyone know what's going on?? I dont know whether I should carry on with the armour, but I'm 3 days in now, getting worse by the day!

It's going to be a while before I go back to the endo. One improvement on the Armour is that I'm sleeping like a baby!

Does anyone else feel like a mad scientist??

4 Replies

I think you should stop. Your body is telling you and you should listen to it. Of course we cannot do without thyroid hormones. Try taking an anti-histamine 1 hour before taking Armour tomorrow. If you don't have a reaction there is something in the fillers/binders that don't agree and you'll have to go back to Erfa or Nature-throid or wpure both of these last two are hypoallergenic.

"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"


Erfa and Armour are different strengths.

Erfa has 35mcg levothyroxine (T4) and 8mcg liothyronine (T3) per grain (60mg)

Armour 38mcg levothyroxine (T4) and 9mcg liothyronine (T3) per grain (60mg)

This is from the ThyroidUK website

Click on the bar which says 'Non-UK - Desiccated Thyroid' for NDTs and their ingredients. You'll also find the fillers listed, which may be a problem.

I changed from Erfa to Nature-Throid and had to reduce my dose.

If you are getting a private prescription I think you'll find that Nature-Throid is cheaper than Armour.

It might also be worth checking the expiry date for your Armour. They do degrade with time.


Anthea is right in as much as one grain of Erfa does not equal one grain of Armour, that's a very important point.

In addition to that I would like to add that you cannot switch around so quickly. It takes about six weeks to equilibrate on either medication. That is one of the problems, it is a very slow process to get on the perfect dose. It's 6 weeks per try and if you are very sensitive to dose it can take years to get to the correct one. Then you feel great that you have achieved your goal - but NOoooooo, then they discontinue that make of pill and you are back to square one!


Dosing with NDT can be an inexact science for some because each brand of NDT has different excipients (additives) that can effect absorption. You may not be absorbing the Armour as well as you absorbed the Erfa. You might try grinding or crushing the Armour into as fine a powder as you can and try it that way.

While you are working all this out, it might be worthwhile to track your body temp and heart rate, taking both a few times per day and keeping a log along with your NDT dosage. Remember... before the development of the cursed TSH test, the only way doctors were able to dose NDT was by relief of symptoms, body temp and heart rate.


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