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Thyroid UK
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When to stop taking t3 preblood tests

I'm only on t3. I have a blood test at 9am in August, when should I stop taking my t3?

I having the bloods taking at 9am for cortisol and all my thyroid functions, but the blood form where my endo has filled it out is unclear... I see it says, tsh, then in hand writing ftf and ft...??.

I remember last time I did the cortisol test I had to take a steroid the night before, but on this occasion, I'm not doing that... What will the cortisol test show?

Many thank you


7 Replies

You can take T3 the morning before your blood test allowing around 24 hours between T3 and test which should be as early as possible and fasting. You can drink water. Take T3 afterwards. ftf and ft may mean free t four and free t 3.


thank you shaws...sorry my mistake it's not "ftf" it's tft :)


Oh well - GP will have to interpret :)


Do you know much about cortisol tests Shaws?


I'm sorry Nikki I don't but this is a link and don't know if it will be helpful.


Also put up a new post with the heading 'Cortisol Tests?'

1 like

TFT stands for Thyroid Function Test. Clemmie


Nikki, leave 24 hours between last dose and blood draw.


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