Thyroid UK
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Uh oh! Taken too much Armour!!

My stupid T3 starved mashed potato brain has got mixed up and I've taken a double dose of Armour!

I don't know what to expect. Should I stay home and take it easy or does Armour act over the longer term?

My usual dose is 30mcg T3 & 25mcg T4 (equivalent of 175mcg T4) though I've been on 150mcg of T4 only for a while due to the shortage of T3. I don't do well on T4 only and not been too great.

This is the first time I've taken Armour and (despite knowing that my prescription should be one 2 grain tablet per day!!) I've taken two tablets yesterday afternoon and again this morning.

From what I understand, 2 grains of Armour is equivalent potency to 148mcg T4..? So I've effectively taken the equivalent potency of 300mcg T4 two days in a row.

I'm feeling okay so far except for nasty headache but only took today's double dose an hour ago. I've felt overdosed once before and wasn't nice! Should I prepare to feel rough? :-/

9 Replies

You may not feel too bad or you could feel quite overstimulated. Just miss out tomorrow's dose and things should settle down.

Before the synthetic TSH blood tests became the norm people were dosed according to clinical symptoms and the average was between 200mcg and 400mcg daily.


Thanks Shaws, that's good to know. :-)


I am just reading Dr S book and he describes a few exampels of people over medicated with thyroid hormone. He doesn't seem to be too concerned about it particularly if it is a one off( or 2 off). He was talking about people taking 600mcg and more.I was taking 300 mcg for 20+ years which was the correct dose for me and I was not thyrotoxic. I dont think you need to be worried. I take at the moment 1 grain and 125mcg thyroxine and I am hypo( which would be 275 I suppose)I am working up to taking 2 grains and 100mcg thyroxine.



Thanks Roslin, I'm not thinking ill have done any damage by a double dose, just whether I'm likely to feel rough. (Don't know how quickly Armour acts by comparison to T4/T3).

Your current dose sounds quite low if your optimum dose is 300mcg... Isn't one grain only equivalent to 74mcg T4, therefore you're only taking equiv of 199?


I have great difficulty getting my head around it(brain fog)but I was thinking that T3 is 3-4x T4 so 1 grain would be about 150 mcg T4 ( but you probably cant work it out like that because T4 has such a short 1/2 life)Get very confused but I think you will be fine.



T4 has an eight day half life but the t3 has only a few hours. Hope you are alright

Jo xx


Your right, just shows how muddled I am.




I think it got missed. The desiccated thyroid makers have at times suggested something like 100 micrograms of levothyroxine being equivalent to one grain (60 milligrams) of desiccated thyroid. However, that seems to be "playing safe" and a more realistic value is indeed around 75 micrograms of levothyroxine.



600 micrograms of levothyroxine is standard for testing on humans in the USA.

Much higher doses have been used without significant problems.

Indeed, there are many stories of district nurses giving an entire week's levothyroxine dose in one go.

The other day I posted an answer in which I referred to the story of a 2 year old child who took (if I remember correctly) 40 tablets of 150 micrograms in one go.

And the vet who took animal levothyroxine (which is in much higher doses than human):

Unfortunately, the poster I was responding to seems to have taken down their questions/blogs.

I do appreciate that desiccated thyroid also has T3. But overall, it has an impressive safety record over a very long history.


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