Why should I be splitting dose the day before bloods? I take 112 mcg t4 and 20 mcg t3 in one go, my ft4 is mid-range and ft3 is over 70-75% after taking my dose 24 hrs before the test. I have heard it is recommend to test ft3 8-12 hrs after the last dose.
I think jimh111 you have mentioned based on half life of t3 the actual reading difference would be minimal, like adding around more less 10% on top of the result (of course everyone metabolises it differently), tsh would be a tad lower, not sure about ft4.
When someone splits a dose day before testing and let's say they take it twice a day and maybe twice a day their ft3 is 75% range, and someone who tests after 24 hours with same result 75% range, does it not mean that possibly the person that splits takes way too much, should they not have slightly lower levels and more consistent maybe, but if they took all in one dose surely they would be over range in the morning? I can't seem to be able to figure out the rationale of it, need some help please or I'm starting to suspect bloods are quite unreliable for ft3 levels.