T3

[Pixielula]

Does anyone know if you take T3 how long will it take to get out of your system and your function go back to normal, for a blood test.

[diogenes Remembering]

The half life of T3 is about 1 day, so that half is left after 24 hr, and only one quarter after two days, and one eighth after three. That's assuming you take no more in that period.

[greygoose]

The FT3 might drop quite quickly, but the TSH is going to take much longer to change. And, as it's unpredictable, I don't think anyone can tell you how long that will take.

[Pixielula]

Thanks for the quick reply’s, it was the THS that I was after, would maybe a month be long enough?

[Judithdalston]

Are you trying to get your bloods ie TSH acceptable for Gp , say for annual review, and remove all traces of the T3 you take including your TSH which is now down well well below range? I had wondered how to this myself for annual diabetes review in December, I'm on a T4 125 mcg/T3 25 mcg combo, but was hoping it was more like days than a month. Be interested to see what you do, and if it works.

[Pixielula in reply to Judithdalston]

Sorry my reply’s have gone in the wrong order, it seems to be a new format!

[Pixielula]

My daughter and I are pretty sure her thyroid is going, in January she had a blood test that showed a ths of nearly 3 and virtually no ferritin, Dr said thyroid is fine and started her on iron tablets, so after a few months she did start to feel better but then went back downhill again. I suggested a private blood test that would show her antibody numbers. She wanted to trail some thyroid meds to see if that would help and I think prove to her that it is in fact her thyroid, I only take T3 so she has been taking 10mcg a day for the last two weeks. She is now worried that the blood test for the antibodies will show a lower tsh. I advised she need to tell her GP that she has been taking T3 but she is worried about that, so it’s tricky as I know she won’t get any treatment until her ths gets much higher even with antibodies present. So that’s the problem really, she wants to go fully armed with her blood test to her GP but can’t have her bloods done until she feels her ths is back to its normal level. She had her GP test done mid morning after food.....

[Pixielula in reply to Pixielula]

Her T4 was only just over the lower end of range and of course no T3 was done

[jimh111]

The T3 will be out within a week and TSH responds rapidly. However, if you suppress the TSH for a long time with high doses of T3 (or T4) then the TSH may stay down permanently. This is very unlikely to happen in this case with just 10 mcg L-T3.

[Pixielula in reply to jimh111]

Yes and she has only taken it for two weeks, I don’t want to waste money on the blood test till we know they are her normal levels.....

[Judithdalston in reply to Pixielula]

It's ok - just read all the replies- JimH sounds bit more helpful re your daughter...our bodies all seem to behave differently thus we sometimes get a range of answers. Don't like idea TSH stays down permanently! Good luck.

[jimh111 in reply to Pixielula]

I thought you were concerned about a blood test by the GP and they usually measure TSH only. If you are doing a private test it should include TSH, fT3 and fT4. In this case I would give it a month so that the fT4 figure can recover, TSH will recover quickly but since T4 has a seven day half life it takes a while to build up in the system. Two weeks would probably be long enough but four weeks would be certain.

[Pixielula in reply to jimh111]

Yeah we are getting the T3 T4 thyroglobulin and thyroid peroxide antibodies and that includes the ths as well, my daughter want to try for s baby later this year so her urgency to get this sorted is acute. Thank you for all the advice and help ....