switched to armour: So I was taking 5 mcg of... - Thyroid UK

Thyroid UK
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switched to armour


So I was taking 5 mcg of cytomel a day and alternating 50/75 mcg of synthroid daily until last week. A week ago i went on 1 grain of armour (60mcg) and i am starting to feel a little more tired. I was told the 1 grain of armour would be sufficient but i don't believe so. It is not as easy to get out of bed the last 2 days and i was falling asleep on the couch in the evening the last 2 nights after sitting down for a few mins. The dr told me the 1 grain is equal to 100 of synthroid but i do not believe that at all. I was taking @ 75-80 altogether with my synthetic combo and now on 60 mcg. I understand that ratio is different on NDT of T4 and T3 but this is not enough. What do you all think?

6 Replies

1 grain of armour is 60mg and contains 38mcg T4 and 9mcg T3.

T3 is supposed to be 3 times more potent than T4 so 9mcg T3 = 27mcg T4.

38+27 = 65mcg T4 equivalent

Not sure where your doctor gets 1 grain is equivalent to 100mcg synthroid from???


in reply to SeasideSusie

That's what the makers of WP Thyroid and Nature-throid state on their website. It is the 'effect' of the tablet on the body, I believe because it contains T3.

I really didn't see this dose comparing to my previous combo.


Your doctor is correct in that NDTs are usually stated as approx 100mcg of levo. Some patients may find them not as strong as they expect but the best way to introduce is to switch straight over, as you've done, to an equivalent levo dose. It's the same with levo, some feel fine on 100mcg whilst others may need 300mcg.

Now that you are experiencing symptoms you should increase your dose by 1/4 and do so every two weeks till you are symptom-free - (no blood tests should be required) - and I'll give you a link which will be helpful.

We need sufficient thyroid hormones to eradicate all our miserable symptoms but sometimes we have to switch-over to another after a suitable time has elapsed. It's no good switching to this make or another every few weeks later.



(I am not medically qualified)


Manufacturer's claim 1 grain (65mcg combined T4+T3) is bioequivalent to 100mcg Levothyroxine ie the effect with the T3 added is like taking 100mcg.

You were already taking 77.5mcg combined T4+T3 which is more than the 1 grain combined dose so your endo has reduced your dose.

in reply to Clutter

yeah i definitely think i need another 1/4 grain to put e where i was. I am going to give it another week and then cal and demand a little more. This definitely is not enough. Although i feel good like this maybe good for me (the NDT in itself)

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