HELP NEEDED RE: BLOOD TESTS FOR T3/T4 COMBINATION

[JGBH]

Hello,

I have started taking T4/T3 combination therapy at the end of last year. Am due to see the endocrinologist for a review soon and am planning to go for my blood tests tomorrow morning, at 8 am.

I know that Levothyroxine must not be taken for 24 hours, that's easy as I have done so for a long time. However, am not sure about T3. I have read it should be stopped either 8 or 12 hours before testing. So which is it, and how best to do it?

I usually take 20 mcg T3 with 75 mcg T4 at 6.30 every morning then 20 mcg T3 between 6.30 and 7.30 pm in the evenings. Any advice on how I will need to take T3 this evening? Will I need to split my 20 mcg dose in 2, taking 10 mcg at 4.30 pm then the other 10 mcgT3 at midnight, leaving an 8 hour gap before blood tests, then taking both 20 mcg T3 and 75 mcg T4 straight after the blood tests?

Apologies for the short notice.

Would appreciate greatly your advice as usual.

Many thanks.

[SlowDragon Administrator]

Suggest you split 2nd 20mcg ....10mcg 3pm approx

Last 10mcg at 9-10pm ...assuming blood test at 9am

[JGBH in reply to SlowDragon]

Thank you. Blood test is at 8 am.

[SlowDragon Administrator in reply to JGBH]

So perhaps take last 10mcg at 8pm or 9pm latest

[SeasideSusie Remembering]

JGBH

I have read it should be stopped either 8 or 12 hours before testing. So which is it, and how best to do it?

Advice is to stop T3 8-12 hours before test not 8 or 12 hours.

As your blood test is at 8am tomorrow, then last dose can be any time between 8pm and midnight tonight.

[JGBH in reply to SeasideSusie]

Many thanks. Will make a note for future tests. Do hope there will be future T3 tests if endo agrees to carry on prescribing after the 3 months trial.

[SeasideSusie Remembering in reply to JGBH]

There should be, but it will be worth mentioning to him something along the lines of "As I'm continuing with T3 then I assume the FT3 test will be included in my thyroid function tests in the future? How does my GP go about ensuring that it's tested as sometimes the lab doesn't carry out the test when requeted?" sort of thing.

[JGBH in reply to SeasideSusie]

Thanks again. I do hope he will keep on prescribing. Because I see the endo at a different hospital, further away from where I live we (the endo, my Gp and I) have come to an agreement regarding blood tests.. Endo tells me which tests to do and then I ask my GP to give me the forms... so far she has agreed (it would mean I would have to go again to the hospital at a distance several times, and am not well enough to do so). Then I give the endo my blood results when I see him. So fingers crossed.

[Marz]

Is your Endo sympathetic to T3 ? I seem to remember you are having a trial run.

If you want to keep Endo on side I would take your usual T3 dose at 6pm and dose again after the test. This should give you an in range T3 and not alarm the Endo 🤩 Also taking it the way you suggest should produce an in range result.

Adjusting the result by say 10% will give an approximate true reading.

I didn't take my T3 for 24 hours so that my very new UK GP was not too shocked !

How are you feeling ? Others here will have other suggestions. T3 remains for around 8 hours I have read ...

[JGBH]

The endo did say he thought I needed T3 in combination with levo, but yes as a 3 month trial period. Rewiev is coming up shortly, quite nervous.

Your suggestion of my taking my full 20 mcg T3 dose at 6 pm and then again after the blood test at 8 am tomorrow morning after test gives a 14 hour gap.... I think that's too much of a gap. GPs have no idea so would not trust them on such a matter.

It did not seem to do much for me, to begin with because I decided to start taking a much lower dose than suggested by endo (told him so and he agreed), so low and slowly increased dose till I took the 40 mcg/day (in 2 doses) as recommended. However, my hair does not fall as it used to, and since I have been on the full 40 mcg/day (2 weeks now) I have felt a tiny bit of energy coming back, not big and does not last long, but it's a start I hope.

I am aware it takes much longer than 3 months to find out what dose is required to really make a difference. Still feeling pretty rough but I do have other serious health problems.

Hope you're ok,

[Marz in reply to JGBH]

My suggestion was to ensure your FT3 did not come in too high and scare the Endo !

[JGBH in reply to Marz]

I somehow doubt (but could be wrong) my T3 will be too high.... it's always been very low and have just taken the full 40 mcg/day in 2 doses for past 2 weeks. Will see. Should it come very high I will simply tell him I made a mistake in taking my last dose very late before blood test because I had forgotten,,, Fingers crossed.

[Marz in reply to JGBH]

Hope all goes well with your Endo appointment ... ☆

[JGBH in reply to Marz]

Thanks Marx. Blood tests today appointment in 2 weeks.

[Marz in reply to JGBH]

Marz

[SlowDragon Administrator]

10pm to 9am.....is 11 hours

[SlowDragon Administrator]

You also need vitamin D, folate, B12 and ferritin tested

What vitamin supplements are you currently taking?

[JGBH in reply to SlowDragon]

Sent you a reply re: other tests half an hour ago but forgot to send it to you directly. Hope you can see it...

[SlowDragon Administrator]

Many of us take dose split into 3 doses, through the day....everyday

[JGBH]

This was in reply to SlowDragon : All the endo requested was: FT4, FT3, TSH and SHBG (sex hormone binding globulin). So I asked my GP to add FBC, VitD, folate, ferritin. She added B12 (which really should not be trsted again once one self inject regularly, which I do). I also requested CRP ESR(have much inflammation) and she also added: LFT, PTFRNS, UE.