How long to wait for t3 to leave for test?

[ratqueenxo]

Hello,

I am due for a thyroid test soon after having very low T3, my endo was dubious of my hashimotos diagnoses by a functional doctor(I am however not).

I was taking T3 for around 3-4 weeks, only 10mg of a 25 mg dose (thybon henning).

I've been off it only for around 10 days, he said I could get retested after 10 days being off of it.

Is this accurate or should I wait longer? I want an authentic reading as possible since I will probably have to convince him I'm sick.

My t3 was MINUS 2.3 so I'm not sure why he didn't raise medication questions, but I'll see when I get there.

[tattybogle]

10 days should in theory be long enough for the added T3 to have left your system. But that does not mean it's long enough for your TSH / fT4 /fT3 results to revert to their 'natural' state .

TSH can often take a few weeks (at least) to settle back to it's normal .. and as TSH changes , it affects the thyroid's production of T4 and T3 .. and it also affects the conversion of T4 to T3 in the body. So definitely the TSH and possibly the fT4 /fT3 results could all be expected to continue changing for a lot longer than 10 days .

As long as this is borne in mind there is no reason you can't test @10 days .. but if those result don't get you what you want ,, then insist on retesting after 6-8 weeks.

[ratqueenxo in reply to tattybogle]

Awesome, thank you so much!

[Kapuna]

I was told that T4 stays in your system but T3 doesn’t last more than a half a day so am/pm dosage works better than a single daily dose.

[tattybogle in reply to Kapuna]

Not quite .. T4 has a half life of about 7 days in blood .

T3 has a half life of about 1 or 2 days in blood. (can't remember exact time off top of my head) this means after 1 or 2 days 'half of what you took has gone' (less any you used) . after another 1 or 2 days 'half of that remaining half has gone' (less any that you used)

But once within the cells . T3 continues to have it's action for 2 or 3 days . Hence some poeple are fine taking it in one daily dose . The reason for split dosing of T3 is to smooth out the effect for those that feel it , not everyone does and to moderate the highish fT3 levels in blood that happen when a full daily dose is absorbed from the gut all in one go.

[shaws Administrator in reply to Kapuna]

I follow a scientist/researcher/doctor who took T3 himself and he advised taking one daily dose of T3 with a glass of water that saturated all of the T3 receptor cells and stated that the effect of that one dose can last up to three days.

DrLowe is now a deceased scientist (due to an accident). His name was Dr John Lowe, who was also an Adviser to TUK (thyroiduk).

I trialled that myself by taking my usual one daily dose of T3 and toook none on day 2 or day 3 and, yes the one dose lasted three days.

The following link may be helpful:-

tpauk.com/main/article/dr-j...