Testing after Change in T3 dose.

[lucylocks]

Hi

how long is it best to wait to test FT3 level after a dose change.

Thank you.

[SlowDragon Administrator]

6-8 weeks minimum....a bit longer might be better

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .

Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

If/when also on T3, make sure to take last third or half of daily dose 8-12 hours prior to test, even if this means adjusting time or splitting of dose day before test

[lucylocks in reply to SlowDragon]

Thank you,

I am asking for my daughter who takes T3 only

She reduced her dose recently after getting a very high FT3 level result. I thought I read on here somewhere that you do not have to wait 6 to 8 weeks as you do with levo.. hence the question.

[Pixipot]

I notice that there's a lot of people on here seem to understand the blood test results, how did you learn what all the terminology means? I'm overwhelmed by how one minute I'm ready to be taken completely off levothyroxine because readings were "normal" only to be told no dont come off and been given an iron tablet daily and D3 too after another Doctor checks them.

[lucylocks in reply to Pixipot]

Hi Pixipot,

I would post a new question as a lot of members won't see this.

Regards.

[SlowDragon Administrator in reply to Pixipot]

Write up your own post and members will help

[vocalEK in reply to Pixipot]

My mind is boggled by a doctor who wants you to stop replacing your missing thyroid hormone because now that you are medicating, the levels are normal. Guess that doctor doesn't understand the concept of "replacement." Does he or she actually expect that once you take away the replacement, your thyroid gland will suddenly start producing more hormones on its own?