T3 and blood test

[JAmanda]

@Slowdragon I've made a mistake and have taken my meds at the usual time (7am 100 Levo and 20 Lio) and am due to have blood test at 8am tomorrow. I usually split my lio dose so take half 12 hours before test but have obviously messed that up this time.

I just saw Slowdrsgon saying that one should take last 1/4-1/3 10-12 hours before... should I take a little bit tonight extra or just leave it? Will my results be much affected? It's an expensive test so I don't want it to be a waste of time. Many thanks.

[koala46]

Any dose of T3 should be taken at least 12 hours before the blood test. T4 around 24 hours before. If it's not the case then results will be inaccurate

[SeasideSusie Remembering in reply to koala46]

Koala46

Any dose of T3 should be taken at least 12 hours before the blood test.

We always advise here that last dose of T3 (and NDT) should be taken 8-12 hours before the blood test, not more than 12 hours which your reply implies.

JAmanda Personally, I wouldn't take extra T3, it may give a false high FT3 result if you take more than your normal daily amount of T3 before the test. By taking your T3 in one dose rather than splitting, and with the time gap being 25 hours, your result may show an FT3 result a bit lower than normal circulating amount but you could take that into account, personally I think that's better than having a false high. However, SlowDragon will comment, I'm sure, when she sees your post.

[SlowDragon Administrator]

No don’t take any extra T3

Just accept Ft3 level will be slightly lower in test results than it should have been

If taking any supplements that contain biotin you need to have stopped taking a week before blood test

[JAmanda in reply to SlowDragon]

Many thanks.