On 1/4/09 2:00 AM, Holly Jagger <[log in to unmask]> wrote:
> Subject: accurate conversion table?
> Does anyone have a link or suggestion, I am looking for an accurate
> conversion table for Synthroid and Armour.
<snip> 
> And 1 grain Armour would have 74 mcg T4 activity, if all converted over.
> [38 mcg T4 plus (9 mcg T3 X4)]

Hello Holly, I realize this is an older post, so you probably have the info
you need now.

You are right to say that 1 grain of Armour has 3/4 the potency of .1 mg of
Synthroid.  it is important to know that all natural thyroid supplements are
not equal.  Here is an old post of mine regarding equivalencies and potency:

On the basis of Dr. Michael's statement that T3 has 4 times the activity of
T4:

We conclude that 1 grain of ARMOUR is NOT equivalent to .1 mg
Synthroid.  This does not necessarily apply to all T4/T3 supplements (i.e.
synthetic Thyrolar).

Armour 1 Grain contains 38.0 mcg of T4 and 9.0 mcg of T3.
That's a ratio of 4.2 to 1.0 [Activity:  38 + 36 = 74 mcg T4 equivalent]

Ergo ACTIVITY level of 1 grain Armour is only 3/4 that of .1 mg Synthroid.

Armour 1/2 Grain contains 19.0 mcg T4 and 4.5 mcg T3.
Thats a ratio of 4.2   [Activity:  19 + 18 = 37 mcg T4 equivalent]
~~~~~~~~~

However, 1 grain of Thyrolar IS equivalent to .1 mg Synthroid (see below):

Thyrolar 1 contains 50 mcg of T4 and 12.5 mcg of T3
That's a ratio of 4 to 1. [Activity:  50 + 50 = 100 mcg T4 equivalent]

The important thing here is having a number for the "activity" level of T3
compared to T4.
~~~~~~~~~

This said, here is an "equivalency" chart from a Canadian Pharmacy book, but
remember that all natural thyroid supplements are not equal.
[note that the desiccated thyroid refers to "Thyroid" made by Parke Davis]:

mg            Desiccated     Dose of T4          Dose of T3
equivalent    thyroid        levothyroxine       liothyronine
                  (grain)
 32                 0.5                0.05                12.5
 65                 1                   0.1                  25
130                2                   0.2                  50
200                3                   0.3                  75
260                4                   0.4                100
325                5                   0.5                125

(1 grain) = 60 mg of Thyroid
~~~~~~~~~

I hope I haven't confused you too much.  The important things to remember
are:

1)  start slow
2)  cut back on T4 (Synthroid) if adding T3 to the mix
3)  ACTIVITY level of 1 grain Armour is only 3/4 that of .1 mg Synthroid
4)  1 grain of Thyrolar IS equivalent to .1 mg Synthroid


Joan McPhee, MH, WT
mailto:[log in to unmask]

---Please do not interpret my comments as medical advice or as a substitute
for a visit to your healthcare provider.---



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