Levo and afternoon blood test

[AleB]

Could anybody advise please, I generally do blood test first thing on a morning, then take Levo straight after. Owing to the current situation (Covid) I have done well to even get a blood test through GP, however I can only get a 2pm appointment! My question is, do I still leave off Levo meds until after blood is taken? Would it give ma a slightly inaccurate picture of T3, T4 and Tsh? Only reason I have requested bloods is because ever since I had to go back to Levo I have really struggled with brain fog, weight, headaches and inflammation. I have also requested stool analysis and inflammatory markers as I seem to have problems again with GI tract and gut. I have recently started selenium to try and help with conversion, but too early to say if this helps. I am trying to find the right adaptogens, still GF and DF. My adrenals took a battering back in February, coming off NDT, but my blood sugar has been all over the place!

Thank you to anyone who can offer advice.

[SeasideSusie Remembering]

AleB

The reason for an early morning test is to get as high a TSH as possible for those looking for a diagnosis, to avoid a reduction in dose of Levo or when looking for an increase in dose. If TSH is not important then it's not essential to do an early morning test.

However, it is important to measure your normal amount of circulating hormone (FT4/FT3) and that is why a certain time gap is recommended between last dose of hormone replacement and blood draw.

If on Levo - last dose is 24 hours before blood draw, adjust time the day before if necessary.

If on T3 or NDT - last dose is 8-12 hours before blood draw, adjust time the day before if necessary.

If you take your hormone replacement too close to the blood draw you will get a false high result for your hormone levels, if taken too far away from the blood draw then you get a false low result for your hormone levels.

[greygoose]

You sure bout that? If the OP is on levo only - which I assume she is as she talks about coming off NDT - and her blood draw is 2 pm, she would need to take her last dose at 2 pm the day before.

AleB, if you take your levo in the morning, as usual, and your blood draw at 2 pm, then you are going to have a false high FT4. It won't affect your FT3. Your TSH is affected by the time of day, and at 2 pm, it will be around its lowest.

[AleB in reply to greygoose]

Hello Greygoose, so take the Sunday dose at 2pm?

[greygoose in reply to AleB]

If you're having the test on Monday afternoon, yes.

[AleB in reply to greygoose]

As always, thank you for your help. 😊.

[greygoose in reply to AleB]

You're very welcome.

[greygoose]

Was it better than this one? If so, I'm coming with you, next time.

[AleB]

Thank you for your help, so if I take the Levo dose on Saturday in the morning as usual, and then Sunday at 2pm, then I should be OK for blood test at 2pm Monday?

[AleB]

Hello Scrumbler, thank you for clarifying I really appreciate your help. Have to say, the 2 years I have used this forum I have received a lot of help and support, I have learnt so much and still continue to learn. Thank you all.