T3 only

[bossbird]

I'm currently taking 4 grains armour and 20mgc t3 soon to change to t3 only how much t3 is the equivalent

[shaws Administrator]

20mcg of T3 is approx 80mcg levo, 25mcg T3 is around 100mcg levo.

1 gr of NDT is equal to around 100mcg of levo.

[bossbird in reply to shaws]

thanks that's a worry as my endo has suggested replacing the 4 grains and 20 mgc per day with 3 x 20mgc doesn't sound enough!!

[shaws Administrator in reply to bossbird]

I read on a post yesterday that 60mcg of T3 is the largest amount they can prescribe. 3 x 20mg approx 240 mcg levo. Probably the guidelines.

So you will be well short as he has halved your amount from approx 480 to 240!

I would give it a try initially, as it is T3 only and may work more effectively in you than the NDT. If not, you will have to tell him to come up with another idea and as soon as your symptoms return make an appointment to see him again.

If ONLY the could treat us like they used to do: Read first two questions/answers:-

web.archive.org/web/2010103...

[marmaris in reply to shaws]

Sorry to ask Shaws but I thought it was a 3.1 ratio ie 20mcg of T3 = 60mcgs of Levo. I am currently taking 30mcgs of T3 and 50mcgs of Levo T4 and was led to believe that this was the equavelent of 140mcgs of Levo?

[helvella Administrator Thyroid UK in reply to marmaris]

There is no absolute ratio. There is only a "maybe this ratio would be a reasonable place to start".

Once the first bit of liothyronine (from whatever source) passes your lips, you are a living experiment in which the results are not exactly predictable - only very broad brush estimates are possible.

Do bear in mind that if you were not converting any of that T4 at all, your dose would be equivalent to 30mcg T3. If you back-convert that would be 90mcg T4. Changing your T4 up or down would have no effect. (I doubt anyone is entirely unable to convert any T4 to T3, but the efficiency of so doing will vary. This comment is for illustration by considering a hypothetical extreme case.)

Rod

[marmaris in reply to helvella]

This is all very confusing and one thing always remains in my mind is how do they know exactly if we are not converting T4 to T3 as there is no test of yet to determine what is going on at cellular level. Would you agree with that Rod?

[shaws Administrator in reply to marmaris]

Dr Toft substitutes 10mcg for 50mcg levo. But this is an equivalence chart:-

This is an excerpt from the link below:

Liothyronine is four times more potent than levothyroxine. Levothyroxine 100 mcg daily would be equal to 25 mcg of liothyronine. This is approximately equivalent to one grain of the desiccated thyroid medications.

suite.io/melissa-murfin/27q...

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Bossbird, 4 grains of Armour provides 36 mcg of T3, which together with the 20 mcg T3 you also take, provides 56 mcg in total. As your GP is going to switch you to 60mcg T3 that gives you an additional 4mcg in simple terms. But of course the 4 grains of Armour have also been providing you with 144mcg T4 for conversion to T3.