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Thyroid UK
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NDT and blood test


Hope someone can advise. I have a Medichecks test here and want to take the test tomorrow.

I am on WP thyroid x2 a day.

Dose 1 at 7am and 2nd at around 3.30pm.

Do I just take the 7am dose after I've done my test in the morning?

Slightly confused as I've read on previous posts that I should leave 24 hours. Does that only apply to Levo?


4 Replies

You don't take morning dose until after the test. I myself would not take the 3.30 p.m. dose before the test.

The 24 hours usually applies to levo but I'd still leave 24 hours as I wouldn't want any adjustments to my dose if I was feeling o.k.


If your test includes ft3, then your last dose needs to be between 8-12 hrs before test. o that would mean adjusting your afternoon dose to be night-time. 3:30 is too early and would give you a falsely low ft3 reading. The 24hr rule applies to t4 only, anything with t3 is 12 hours.


I hear different regarding this and I myself have posted before on this question with conflicting answers but usually it's 12 hr with ndt ...I'm also doing medichecks tomorrow morning so instead of taking my dose all at once this morning I've split it for today and will be taking my last half grain tonight approx 8.30pm for 8.30 test in the morning then I'll take tomorrow's dose straight after .

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I am on NDT and have just had my blood test done. I took one grain the day before the test at 2.30 pm in the afternoon and then nothing until after the test which was at at 8am the next morning.

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