Blood test rules for T3

[Redporti]

I’m going to be doing a Medichecks finger prick blood test in the morning. I will be testing TSH, FT4 & FT3. I am currently taking Levo 75mcg at 23.45 and Liothyronine 5mcg at 8.40am and 5mcg at 16.40. I will be doing the test at 8.20am tomorrow. When should I stop the two meds before my blood test? I have taken my morning dose of T3 this morning.

[SeasideSusie Remembering]

Redporti

I, too, will be doing one tomorrow and we need to adjust timing of meds today.

Levo should be 24 hours before blood draw and last dose of T3 8-12 hours before blood draw.

As you take your Levo at night, you can't take tonight's dose at 23.45 and do the test at 8.20 tomorrow as that would be only 8 hours 35 mins and this will give a false high FT4 and possibly false high FT3 depending on how much conversion of T4 to T3 you have.

If I were you I'd do the test on Tuesday and time your doses like this.

Take tonight's dose (Sunday's) on Monday morning with your first dose of T3 at 8.40am.

Take Monday's second dose of T3 between 8.30pm and midnight.

Do test at 8.20 on Tuesday morning.

Medichecks should have included a Tracked 24 return envelope which they say will arrive in good time, and by doing the test on Tuesday it should arrive at the lab on Wednesday or Thursday.

[Redporti in reply to SeasideSusie]

Thank you. Unfortunately I ordered the test kit just before they upgraded to Tracked 24 so have the old envelope. I can’t go to the post office as I can’t go out so will have to hope by putting it in the post box it gets there on time.

[NWA6 in reply to Redporti]

Just email Medichecks to send you out another envelope 🤗

[Redporti in reply to NWA6]

I won’t have time to do that as I have a telephone appointment with my Endo next week so need to do the test beginning of this week. I’ll have to hope for the best.

[SeasideSusie Remembering in reply to Redporti]

I can't go and queue at the post office either, they sent me a Tracked 24 envelope as well as my kit had the standard first class envelope, but of course that was sent normal first class so it took a few days to reach me.

Is there no-one you can ask to take it to the post office for you to send it Special Delivery?

Bear in mind that standard first class post is taking a lot longer, my experience recently of sending and receiving first class post is that it's taking up to 5-7 days.

[Redporti in reply to SeasideSusie]

I will put it to the group in my road. Someone might do it for me. Can I send it back first class signed for? I could print the label through Royal Mail website then the person would only have to take it to the post office. Thanks.

[SeasideSusie Remembering in reply to Redporti]

First class signed for says "Aim to deliver next working day, including Saturdays" but they're not getting signatures anyway for any service at the moment although you can track it as there will be a tracking number.

Their website also says "Looking for more security? Guaranteed next-day delivery with Royal Mail Special Delivery Guaranteed by 9am and 1pm"

Special Delivery is guaranteed next day although they have extended the guaranteed time by a few hours.

The Tracked 24 service is only available to businesses, not the general public.