Sorry if this is asked all the time...

...but how long should you leave between taking a dose of T3 or NDT and having a blood test? OH's test results have come back and FT3 is off the top of the scale but I have a feeling we may not have left enough time between the last dose and taking the blood test.

Thanks in advance for any help.

[Issy]

Certainly dont take the doe thatt day before the blood test - if you do you are only testing the ingestion of the drug.

[Hidden in reply to Issy]

Well, technically it wasn't the same day. But I reckon it might only have been 8 hrs. Probably not long enough!

Results were:

TSH 0.01 (0.27 - 4.2)

FT4 18.7 (12.0 - 22.0)

FT3 10.8 (3.1 - 6.8)

[Moggie in reply to Hidden]

When I was on T3 I used to leave it at least 24hrs - sometimes 48hrs - when having blood tests.

Has your GP said anything to you yet, and if so what?

If he has called you in you need to explain immediately that you made a mistake and took your meds before the bloods.

Moggie x

p.s. If you use the "reply to this" button under my name I will get an email to say you have responded to me - otherwise I may miss your answer.

[Moggie]

12 hours is the minimum and longer would have been advisable.

How long did you leave it? and at what time of day did you have the test.

Moggie x

[Hidden]

Hi Moggie

They were private blood tests (Blue Horizon) so luckily the GP won't see these results - I think if he did he'd take OH off the T3!

Sigh. We'll know better next time.