T3 can also have the effect of reducing FT4 as well as the TSH (I'm assuming those numbers refer to your TSH result, although you haven't said so). However, if you are taking only a quarter of a 20 mcg tablet, ie only 5 mcg per day, I don't know how much effect that will have on your results.
Results are read differently when taking any form of T3 and I don't know if that includes a low dose of T3 but your other results could indicated that it has made a difference. So results when taking T3 show a suppressed TSH, FT4 can fall in its range but FT3 should be high in its range if you are correctly medicated and is the only accurate reading. The fact your doctor suggests dropping your dose says to me that she thinks you are overmedicated as your TSH is suppressed though your FT4 reading is slightly over halfway so low if you were on Levo only. I suspect you haven't a FT3 reading. So your results are possibly confusing her.
Yesterday I picked up my calcium levels from my doctors and find, unknown to me, she has also tested my thyroid levels though I always get them done at the hospital where I'm treated. So I'm taking NDT which my doctor knows about but my resultsxare much like yours, TSH 0.02 and FT4 just halfway and no FT3 reading. The notes attached say that if I am on Levo then my results show over replacement but no clinical notes have been attached to clarify the situation. I need to ask for the calcium I've been taken to go on my list of medications now we know I'm still in range but I must ask her why she requested the Thyroid readings and point out that without testing T3 it is pointless plus tell her the difference in the readings. I'm suspecting that she is worrying about the results on my thyroid from elsewhere and in worried no one is saying the readings are strange! You doctor could well be thinking the same! May be best to ask her why she wants to reduce your dose so that could give you an indication of where she/he is coming from and you need to be prepared to tell her about trying a little T3..Personally I think she should be aware of what you are taking so if you are rushed into hospital for anything its best they know exactly what you are taking in case it's relevant.
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