Thyroid UK
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T3 test privately advice needed

I am considering having the t3 test dne privately as my doctor requested it up the lab did not do it due to a normal tsh. My ft4 is 11.6 (10-20) and dropping, so wondering if my issue is conversion? I need the t3 result to see if this is the case. My question is the test is a finger prick test, is this accurate and under what conditions should I test? Ie. time of day etc .. Thank you.

3 Replies

for time of day: the earliest in the morning will show the highest fT3 result, evening (ie 6-7pm) will show lower fT3, so you do the test at the time you need to do it, if you want a lower fT3 in the evening, if you want a higher fT3 result in the morning (very early, as early as you can)


Thank you.

Not sure if I've dreamt this, but heard midnight is the optimum time for blood tests? Ignore me if In totally wrong, ;-)


well, not so much midnight but 'just after midnight'

that's if you want your TSH to show at its heighest so to get a diagnosis from the NHS!

When my son was due bloods I took it myself at 1am and TSH came back as 6.3.

My TSH was 3.47 at 5:30pm and 4.27 at 8am.

remember thought that fT3 and fT4 follows the same as TSH.

Now that I am 'medicated' and on T3 only if I have a blood test I have it as late as possible in the afternoon (if I can help it) so to show lower fT3 levels :D


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