when to take thyroxine for 11am blood test?

hi there, I have a blood test for my thyroid levels booked for 11am. I currently take my thyroxine in the wee small hours (when I inevitably wake up), so normally around 3am (to avoid clashing with vitamin supplements in the morning, and HRT in the evening).

I can easily fast til after 11 (I can have a drink can I?), but not sure what I should do about taking the levothyroxine?

Any advice gratefully received (i had no idea til I came on this site recently that time of day or fasting had any impact at all - makes me wonder about all the previous tests...)

thanks in advance


Edited to add: the appointment is in a week's time, so there's time to shift when I take the thyroxine if anyone thinks there might be a better time?

Last edited by

10 Replies

  • Tillyxx Can you change your appointment and get one another day, the first one of the day? That would be better as your TSH is highest then, and if you have it done at the same time each time you can compare results like for like.

    Leave 24 hours after last dose of Levo so instead of taking it that day at 3am, leave it until after the blood draw, so it will be more than 24 hours. It's best to fast but you can drink water.

  • thanks SeasideSusie (can someone remind me how to tag a member I've completely forgotten and can't seem to find how out how...).

    I've struggled to get the 11am one (already moved it from 4.30pm) and I'll have to wait at least a fortnight probably longer for an earlier one. I'm feeling pretty rough (fairly recently diagnosed coeliac and suspect my GF diet may mean I need to reduce the meds) so don't really want to leave it that long.

    Useful to know i should leave the levo til afterwards - might try to inch it a bit later than 3am so not such a long gap. Thanks again.

  • To tag someone Tillyxx you put @ directly in front of their member name (no space) and a list will pop up, click on their name from the list and it will highlight blue.

  • thanks SeasideSusie ;)

  • :)

  • Dare I have a coffee (black if needs be!) tomorrow morning or will that be breaking the fast? Need to get child to school and work til blood test and not sure I will survive without coffee ;). Be stern with me!

  • Tillyxx, if the blood test is only for thyroid, then yes, coffee is ok before the test. Just no thyroid meds :)

  • hi RedApple that's just made my evening - thank you! yes thyroid only - so can i have toast too? if so I'm truly delighted (for some reason I thought i had to fast) :)

  • Tillyxx, some people do say fasting is best, but I personally doubt a slice of toast will make a huge difference. If your test was early morning, it might not be a problem to fast. But as it's not until 11am, I personally wouldn't panic about a slice of toast. :)

  • Thank you!

You may also like...