T3 reducing.

[Diyena]

I've just got all my blood tests out and done a table to compare results since October when I was diagnosed. I've noticed that although my TSH was reducing with each rise in Levothyroxine, and my FT4 was rising but my FT3 has reduced! Why would that be?

Levothyroxine doses were:

0, 25, 50, 75mcg

TSH was 5.89, 5.85, 3.61, then 0.95

FT4 was 13.3 and now is 17.6

FT3 was 4.6 and now is 3.9

[Clutter]

Diyena,

TSH helps stimulate conversion of T4 to T3 and FT3 may drop slightly when TSH drops. An increase in Levothyroxine would raise T4 and T3.

[Diyena in reply to Clutter]

But as my TSH was so low before I raised my dose the last time, won't a further raise cause me to go hyperthyroid?

[Clutter in reply to Diyena]

Diyena,

It's not low TSH which makes you hyperthyroid. It's over range FT4 &/or FT3 which makes you hyperthyroid.

[Diyena in reply to Clutter]

So it's ok to go down to 0 on TSH? Is that 'suppressed'?

[Clutter in reply to Diyena]

Diyena,

<0.1 is suppressed. Mine has been <0.01 since 2012.

[Diyena in reply to Clutter]

From the little I understand, TSH is something that triggers your thyroid to produce T4? So if taking Levothyroxine does that mean it becomes less important?

[Clutter in reply to Diyena]

Diyena,

Yes, once you are taking Levothyroxine TSH really isn't important, it's FT4 and FT3 which matter.

[Diyena in reply to Clutter]

I'm learning gradually 😀

[Clutter in reply to Diyena]

Diyena,

I'm convinced that if only Levothyroxine had suited and my endos had been better I would still be living in blissful ignorance of what hypothyroidism meant