Misunderstood about when to take T3 before blood test?

[cazzaleo]

Hi!

From other posts I’ve read recently I think I’ve misunderstood about when my last T3 dose should be before having blood drawn.

I thought there needed to be at least 12 hours between my last T3 dose and the blood draw. I usually take my T3 about 6 or 7 am, and when I’ve had blood drawn it’s been around 9am.

I’ve therefore left about 26/27 hours between the T3 and the blood draw - have I therefore been getting false low FT3 readings?

And if so, how should I time my T3 in the future? Should I add some in in the evening before my blood draw (I.e. 11 hours before at 9pm) even though I usually take one dose in the morning?

And if this is what I need to do, how much do I take? I currently take 15mcg in one dose in the morning.

Thank you all!

[shaws Administrator]

I get my blood test 24 hours after taking T3 as I take mine first thing when I get up. I am well have have really no interest in my blood test results at all because I am well. All of my blood results are good. I get a yearly blood test.

If I had symptoms then it would be a different matter.

I have read that others state a 12 hour gap when on T3 only which makes it awkward if you take an early a.m. dose.

You could switch to a bedtime dose and miss this and take after test and night dose as usual.

[cazzaleo in reply to shaws]

Thanks for your reply shaws.

I’m definitely not feeling well yet. And I’m hoping to get my private endo to increase my dose of T3, so for now I suppose it wouldn’t be a problem if my FT3 reading seems lower than it should, as it gives me an even stronger argument for the increase.

Having said that, I fully expect that the endo isn’t going to be happy to increase to the level I need and so I’m considering adding in some extra myself. And if/when I do that, I’d like to know that my blood tests results are something I can use as a useful/meaningful guide - along with how I’m feeling.

So maybe I’ll need to switch to an evening dose then.