Blood test

[Runner25]

I’m having t3, t4 and tsh test at 8.30 am on Friday. I’m on t3 and t4 so when should I have my last dose? Also can I eat before? X

[SeasideSusie Remembering]

Runner25

Last dose of Levo - 24 hours before test.

Last dose of T3 - 8-12 hours before test, splitting dose into 2 or 3 the day before and adjusting time if necessary, so last part of dose should be between 8.30pm on Thursday night and 30 minutes past midnight.

Water only is advised before the test, this is because certain foods and drink can affect TSH.

If taking biotin supplement or B Complex or any other supplement containing biotin (B7) stop taking it now as it can give false results for any blood test. If taking a high dose in a stand alone biotin supplement or in a hair/nail supplement, eg 5mg-10mg, then change date of test and leave supplement off for 7 days.

[Runner25 in reply to SeasideSusie]

Thank you that’s great.

[humanbean]

Is it a test done by the NHS? If it is that is fine.

However, it wouldn't be a good idea to do a private test on a Friday (or a Thursday, or possibly even a Wednesday, depending on the postal service used).

If done on a Friday it could end up being delivered on a Saturday when the lab doesn't have any staff. Another issue is if it gets stuck with the Post Office or Royal Mail over the whole weekend. The blood may deteriorate over the weekend.

[Runner25 in reply to humanbean]

It’s Nuffield Health, through Bupa. Hopefully that will be ok.