On another thread I got the conversion wrong on Synthroid to Armour. Please help to understand. In the "FAQ section" for Armour, it gives the equivalancies of 90 mcg/1 1/2 grain to 37.5 cytomel and 150 synthroid. When I posted that, your equavelancy was different. No doubt you have the right info. as I do not take Armour and don't understand it as much as you do. Please set me straight though, as I would really like to understand how this works. I am currently on 100 Synthroid and 10 Cytomel. What would that translate to an Armour dosage?
As you know I have had problems with Armour in the past. But since I have been slowly titrating up on the cytomel, my body seems to tolerate T3 a little better. I still get times that I have some fast heart rate and palps. shortly after I take my cytomel, but it's much better than when I first started the cytomel last fall. I would like to try Armour again someday in the future, if for no other reason than it is much less costly than the synthroid/cytomel prescriptions.
Any help you can give me to understand Armour better would be appreciated.
OK... After seeing their table, I think I see where you're going wrong.
They're saying that 90 mgs of Armour is equal to
37.5 mcgs of T3 or to 150 mcgs of T4.
Not both combined.
Let's see if I can explain this well enough: Each microgram of T3 is four times more potent than each microgram of T4. Therefore, 37.5 mcgs of T3 is as potent as 150 mcgs of T4. ( 37.5 x 4 = 150 )
Also, the chart at their site assumes absolutely perfect cell reception and liver conversion. That's not a realistic assumption. Almost everyone has some degree of difficulty in one or both areas. So, I use a conversion chart that Meep directed us to when I first joined here. I can't name it, but I can give you their suggested conversions below. The high end of the T4 range assumes ideal absorption/conversion. Again, most people will benefit less than ideally from any particular dose.
Each grain (60 mg) of Armour contains 38 mcg of T4 and 9 mcg of T3. The T3 is four times as potent as the same amount of T4, so multiplying 9 x 4 = the rough equivalent of 36 more mcgs of T4. ( 38 + 36 = 74) That explains why the chart below has a broader range of equivalencies than the one at Armour.
Oops... I forgot to answer your question about your current dosage.
The 100 mcgs of T4 plus the 10 Cytomel would be about 140 mcgs of straight T4.
You're taking about the same T3 as you'd get in 1 grain of Armour, but you're taking 2.6 times more T4. If you wanted to duplicate your current dose, you'd have to combine a T4 med with the Armour... So you'd still need 2 prescriptions, which may or may not save you much money. (Although, I think remember someone saying their Cytomel cost them something like $40 a month - maybe more? That seemed very high to me compared to most T4s.)
When my doc originally switched me from Synthroid to Armour, and I had such a hard time, my dosage of synthroid was 112. I switched to 1 1/2 grain (90)of Armour. Based on the information I had (the "combined" dosage of T4/T3 rather than the "or" dosage from the web site), always caused me to wonder why I was prescribed what I thought was a "high" dose of Armour, and maybe I should have started with a lower dosage of Armour. I have wondered that my problems with the switch were really the dosage amount, rather than the ratio fo T4/T3. Based on your explaination, the dosage amount of 1 1/2 grain Armour would have been correct for an equivalent dose of 112 (t4). Right? Had I switched to a lower dose of 1 grain instead of 1 1/2, I would have been short on the amount of T4 I need?
Therefore, I was really prescribed a correct equivalent dosage, and the problems I had was most likely indeed the ratio of T4 to T3 in the Armour. Or there is always the outside chance that something else entirely caused my heart palps, high heart rate, shaking etc. that was not related at all to thyroid meds. Who knows? The only way to be sure is to re-create the situation and see if it happens again---NOT!
Are you still with me...?
If I wanted to go back to Armour, I would need 1 grain + about 50ish mcg. of an additional T4 only medication to give me the equivalent dosage I am currently at???? Right?
It really helps me to be informed to make the right decisions with my doctor, if and when changes in my treatment are necessary. I have come to think the most difficult thing about my thyroid disorder is not being informed enough to fully participate in my treatment when I need to. I much prefer to be "in the know" when it comes time to make good decisions. Thanks again for your your willingness to share your knowledge...you must never retire from this board.
Last edited by Red Maple; 03-30-2007 at 02:32 PM.
Reason: clumsy finger syndrome
When my doc originally switched me from Synthroid to Armour, and I had such a hard time, my dosage of synthroid was 112. I switched to 1 1/2 grain (90)of Armour. ... Based on your explanation, the dosage amount of 1 1/2 grain Armour would have been correct for an equivalent dose of 112 (t4). Right?
While it's technically true that 90 mgs would be a fair trade for 112 mcgs, in reality, I'd rather see the switch made more gradually... because of that sometimes pesky T3. There are real differences in the composition of the two meds that can't be totally ignored when switching. Even though 1 grain would not have contained equivalent T4, IMO, that would have been a more reasonable dose to start out with. It's very possible that was the reason for your difficulty with Armour. That's a large amount of T3 to give someone who hasn't taken any before.
There are no absolute answers to give. (I still don't want to "prescribe" dosages for anyone ) To get the amount of Cytomel you now take, you'll need 1 grain (60 mgs) of Armour. Since it contains 38 mcgs of T4, you'd subtract that from the 100 you now take, leaving 62. That's how much T4 med you'd have to add to the 1 gr Armour to approximate what you now have. (If my math holds up, that is. )
If you want to try Armour again in the future - and the penny-pincher in me thoroughly understands why you would, LOL - I would say to be conservative in dosing and not trying to make an even-steven switch from the outset. Just to be sure what it will do to you or for you.
I don't know if I'll go back to Armour in the future or not, mostly it depends on how I feel, how well I am have adapted to T3 in cytomel, etc. etc. etc. I do however, ALWAYS want to keep my options open, and continue to improve my knowledge of thyroid disorders, meds. available, treatments, etc. etc. etc. I suppose that why I like this board so much and the various experiences and advice it gives. The advice may not always apply to me, and of course the experiences are vastly varied; but it does always give me "food for thought" in how it could relate to my situation. I hope others also benefit in some way when I share my experiences.
You are very correct in that cytomel is expensive and I would like an option there. My co-pay is $50 a month for cytomel, my synthroid is $26.99, but I feel it is really worth the financial investment. A combo of Armour and another T4, may work better financially, but for now I gratefully pay the $76.99 for my medication as this is really the best I have felt in a long time. (still have a bit of a lump in the throat sensation, but its certainly livable) Of course I'd rather put that money toward a lovely new pair of shoes...but if I do not feel well I won't have anywhere to wear my new shoes as I will be home feeling miserable. Ah well, I guess it's going to be the old shoes, and an active life! Small price to pay, huh?
I have also heard, don't know if its true or not, that T3 can exacerbate hot flashes, and other unpleasant symptoms with estrogen hormones. When I finally am post-menopausal, rather that my current state of menopause; when the symptoms and problems I am experiencing decline, perhaps Armour could be more appropriate for me. Have you heard anything, or can you give any credence to the "rumors" about T3 interacting with estrogen fluxuation?
Again, thank you for the information, and a further explaination of how Armour converts to T4 meds. I never know when that knowledge will need to come into play, but at least it will be tucked away in my brain to pull out when I need it!
You are very correct in that cytomel is expensive and I would like an option there. My co-pay is $50 a month for cytomel, my synthroid is $26.99, but I feel it is really worth the financial investment.
Hmmmmm ... I guess I should be very grateful. I have no idea what my co-pay would be for Cytomel, but a 90-day supply of Levothroid costs me $14.90, went up $3 this year. Labs are totally covered and doctor visit co-pay is $15 (only one needed so far).
Thanks for the sympathy ErinBeth. To make it even more of a "dig" from the insurance company...my co-pay is $50, but the retail for 60 5mcg tablets (2x a day) is only $56.99--thanks to the insurance co. I save a whole $6.99. Oh by the way, when I was on only 5mcg (one pill a day) the retail price was cheaper than my co-pay! My labs are also fully covered and doctor co-pay is only $20, but they do get you on the prescriptions.
I try to look on the bright side...at least cytomel is available to me, unlike many people who are on national health care such as our dear sister hypos in England. ...but I'd still rather not need the medication and thus could spend it on shoes...
Wow... that's a hefty chunk of change, RM.
Until 2 months ago, 90 days' worth of Armour was costing me about $22, and that was only about $6 less than full retail price would've been. (My insurer is like most and frowns on name brands, so what they "grant" me doesn't save me much.) Now my insurer is playing a game where they let me have only one month at a time to increase the number of co-pays they can collect. Still, even at that, 3 months will cost less than $30.
Still, whatever works best for us is a genuine good bargain, I think we all agree.
Midwest, as you can see, I'd switch to Armour in a red letter minute if I thought it was right for me! Three months of Armour costs you about $30, thryoid meds for me for three months is about $225. My insurer also will not allow more than one month supply.
Do you have any info. on T3 exacerbating menopausal symptoms? I have heard that it does, and have also heard that there is no connection. Opinions? Truths? Things you may have heard?