Newbie here, I found you looking for RT3 information.
Quick question here. Many years ago, when I was on T4, I was told by a doctor to have my blood test first thing on an empty stomach and then do blood tests. I still do it now that I'm on NDT (once a day; that's changed now, but it was once a day when the blood test I refer to below was taken).
I keep reading wildly conflicting suggestions about timings of meds and blood draws. One FB group says to skip meds the day *before* and until just after the test (so, take Sunday, skip Monday, test Tuesday, take pills Tuesday after test); another group says minimum 12-15 hours after dose. Others say just do it first thing and take pills immediately after.
Wikipedia is letting me down with regard to half life of the T3 in NDT but says the elimination half life of liothyronine is 2.5 days. If it is similar, that suggests that a decent chunk should still have been there at the 24 hour mark.
Any thoughts? I had some confusing results and maybe the timing contributed. It was probably 24-25 hours after the dose at the time of the blood draw.
TSH - low, below range but detectable
FT3 - mid range
FT4 - a quarter of the way up the range
RT3 - high, out of range
Been feeling really hypo and awful lately. Doc changed meds a little after those results and I'm feeling a bit better.