It appears that your current symptoms are due to the med change. You reduced your Armour by 30 mg, which contains 19.5 mcg of T4 and 4.5 of T3. You added 25 mcg of T4. The problems you are experiencing may be due to the difference in half -life of T3 (about one day) compared to T4 (about one week), plus an overall reduction in dosage effects.
When you reduced the Armour by 30 mg, that reduced your T3 by 4.5 mcg, and the effect on serum levels is almost complete in 4-5 days. On the other hand the longer half-life of T4 means that you don't get the full effect of the added 5.5 mcg (19.5 prior, now 25) for 4-5 weeks. The short term effect is a reduction in equivalent dosage.
In addition, using the correct conversion factors, your prior dose of Armour was equivalent to 99 mcg of T4. Your new dosage is equivalent to only 91 mcg of T4, which is almost an 8% reduction.
What were your actual Free T4 and Free T3 results before the med change?
So you felt the need to reduce your Armour dosage due to having occasional hyper type feelings. Due to the difference in half-life of T4 and T3, it would be better to reduce in two steps. First the 25 mcg increase in T4 is almost all offset by the Armour reduction ( 30 mg = 19.5 T4 plus 4.5 mcg of T3). So the incremental 5.5 mcg of T4 is not enough to adequately raise your Free T4. I expect that you will need somewhere between 37.5 and probably 50 mcg of T4 to do that. If you added that much T4, and reduced your Armour by 30 mg, then I would do it in two steps, going halfway each time to avoid the kind of hypo reaction you have had.
As you know the goal of thyroid treatment is to eliminate symptoms. That seems to take Free T4 at least at mid-range, and Free T3 in the upper half of its range, adjusted as needed to relieve symptoms. In addition, there are other variables that are important. Hypo patients are frequently too low in the ranges for Vitamin D, B12 and ferritin. If not tested for those you should do so and then supplement as needed to optimize. D should be at least 50, B12 in the upper part of its range, and ferritin should be at least 70, and some sources say 100. Also if never tested for Reverse T3, I suggest that you ask for that the next time you test for Free T4 and Free T3. Also a good idea to test for cortisol, since it is an antagonist of thyroid hormone and needs to be in reasonable balance.
No, the suggestion was to add up to 50 mcg of T4, while reducing your Armour by 30 mg, and to do it in two steps about 2 weeks apart. Regarding gong back to 90 mg of Armour, I really think that dosage was not right, since your Free T4 was below range, while Free T3 was high in range, plus the occasional reactions. Since you have already started the change, I think it might be best to stay with it, as suggested in two steps. So the first step would be 25 mcg of T4 and 75 mg of Armour. Then the next step would be 37.5 or 50 of T4, and 60 of Armour. Then give that 4-5 weeks and re-test Free T4, Free T3, Reverse T3, and cortisol. Of course all that needs to be discussed with your doctor.
Also, if it has been a while since testing B12 and ferritin, I would re-test and supplement as needed to optimize. B12 should be in the upper end of its very broad range, adn ferritin should be at least 70, and some sources say 100.
You are very welcome. Please let us know how things progress for you.
I would not do that. You have previously had some symptoms, while on 90 of Armour, that you thought were hyper, so you skipped doses. So staying on the 90 of Armour and adding 25 mcg of T4 might cause a reaction. Can't be sure, but hyper symptoms are not very pleasant, so that is why I suggested 75 mg of Armour with the 25 mcg of T4 as the first step.