This might seem obvious to the experts on here, but if you are on T3 only, doesn't your T4 level drop through the floor?
I'm currently taking 2 grains of NDT and between 10 - 15 mcg of T3. My endo was concerned recently because my blood T4 was on the low side although the T3 was in the upper range, and so wanted me to increase the NDT and lower the T3 (her actual words were that she wanted to "wean me off" the T3!). Now, I'm not averse to that since I have recently read about the common mistakes when taking NDT [thanks, Shaws] but at the moment I am not entirely convinced that my body likes T4 anymore (long, long story), so if the increase in NDT doesn't stop the arrhythmia and I don't feel better, I will be wanting to try the T3 only protocol.
Thus my question, if my endo was a bit concerned about the low levels of T4 recently, will she have cause to freak if I'm on T3 only? As in, won't the T4 levels drop away altogether?