Rough equivalence of Armour and Levo.

[Jan49]

Just read Clarebear's answer to another question where she mentions that 3 grains of Armour is roughly equivalent to 225mcg of Levo. Could anyone explain how this is calculated please, I can't find any info. Thanks.

[Jane104]

1 grain is 38mcg T4 + 9mcg T3. It's usually given as being equivalent to 100mcg thyroxine.

The T3 is about 4 times as potent as T4 which would make it equivalent to 36mcg T4. Added to the actual 38mcg T4 = 74mcg T4 which gives Clarebear's 225mcg when multiplied by three (roughly). But desiccated thyroid also contains T2 and T1 so I'm guessing overall it's probably more potent and effective than Levo, so people generally need slightly less and hence the 1 grain = 100mcg Levo.

[Jane104 in reply to Jane104]

So if you were on 225mcg of levothyroxine you probably wouldn't need the 3 grains of Armour, you'd more likely need about 2+1/4 grains.

(Had to write that out loud there cos I nearly confused myself!!)

[boo16 in reply to Jane104]

I would do the calculation as Janericat which shows that T4 of 38 mcg plus T3 of 9 mcg x4 = 74 mcg.

This roughly equates to 75 mcg of Levothyroxine not 100 mcg, which is where Clarebear got her calculation from.

Therefore 3 grains of NDT roughly equals 225 of thyroxine.

I use this myself as a starting point, but ultimately, you need to does by how you feel, not by the conversion....xx

[helvella Administrator Thyroid UK in reply to boo16]

Quite so boo.

Not sure if they still produce any "conversion table" but I think Armour used to say that one grain of Armour should be considered as 100 micrograms of levothyroxine. That was, however, a conservative number to try to make sure that anyone changing over didn't become suddenly over-dosed. A more realistic conversion is, as already said, around 75 micrograms to the grain.

People react differently so any conversion is only an educated guess.

Rod

[boo16 in reply to helvella]

I think Erfa still uses a conversion table, Rod, and I think (without checking - having a lazy day as it is my 65th birthday today and just off out for family lunch), that they equate 60mg tablets as 100 mcg levothyroxine.

Have a good bank holiday weekend everyone xx

[helvella Administrator Thyroid UK in reply to boo16]

Well have a jolly happy one!

[Imogen in reply to boo16]

Happy birthday boo, hope it is very enjoyable.

Imogen

[Jane104 in reply to boo16]

The 2 or 3 conversion tables I've seen all say 1 grain NDT is equivalent to 100mcg thyroxine. I certainly think you need to be cautious in calculating the dose.

Happy birthday Boo!

[boo16]

Thanks Helvella and Imogen for your kind wishes.

Just got back and feeling VERY full and happy. Even had gluten free cake on the menu which was a real treat!

xx

[Heloise]

stopthethyroidmadness.com/s...

[Jan49]

Thanks all for your replies, especially boo- hope you had a great birthday! I'm more confused now to be honest. I started seeing Dr S ahead last Feb and went up to 175mcg of Levo which made me slightly hyper. Next tried adding T3. 20mcg made no difference, 40 was too much. Now I add 1 1/2 grains of Armour so should in theory be overmedicated. Instead I feel more tired, hair is falling out again and am generally worse.

[Jan49]

Meant to say I have a baseline of 150mcg Levo and have been trying to find that extra smidgin for optimal dosage.