tablets before blood test?

[sarah--c]

Hi! Had some great advice from the community here before, thank you!, and one thing that was mentioned was not taking T4 48 hours before blood tests, or T3 24 hours before. Did this, but it seemed to puzzle my endocrinologist. She hasn't said whether or not to take tablets ahead of my next blood test, but I realised I don't really know *why* I'd stop taking them - can anyone educate me, please?

(Background: had half my thyroid removed last year, finally starting to get some medication to treat hypothyroid symptoms, still trying to find the right dose to feel like a proper human being again!)

[SeasideSusie Remembering]

Sarah--c

"one thing that was mentioned was not taking T4 48 hours before blood tests, or T3 24 hours before."

That's incorrect. You leave off Levo for 24 hours and T3 for 12 hours. That gives the normal circulating FT4 and FT3, any longer and you will get false lows.

Some doctors will agree with it, some won't so we don't discuss with doctors or phlebotomists as it's a patient to patient tip.

[sarah--c in reply to SeasideSusie]

Okay, thanks for the correction!