if on t3 only,would it/does it matter if T4 then goes low out of NHS range in the same way as TSH does?

[Gillybean1]

Hi Everyone,

Just trying to understand, as Im bumbling along still not sorted.

2020 I tried 12.5mcg T3 only, with a 1/4grain NDT (cleared out the higher dose NDT over a period of time) . The TSH crashed way out of range and the T4 was 10 (nhs range 12-22)

My question is does it matter that the T4 dropped so low ? and very quickly within days? and is that expected.?

Needless to say, I tried for a year and felt dreadful, I couldnt tolerate higher than 12.5mcg T3, and ended up putting back NDT......5 years on , worse than ever.

Any thought would be greatly appreciated. Every best wish G

[greygoose]

It is most certainly expected, yes. Where would T4 be coming from if you're not taking it.

Whether or not that matters only you can decide. Some people - like me - are fine without any T4 - in fact, I can't tolerate any T4, not even in NDT. But others need their FT4 at a certain level to feel well. It's a very individual thing.

Pretty certain you would feel dreadful on only 12.5 mcg T3 - I take 75! But did you optimise your nutrients and cortisol before attempting T3 only? If they were skewed then it probably would be difficult to raise your dose.

[Gillybean1 in reply to greygoose]

Hey Lovely GG, nice to hear from you.

I wondered if the thyroid would start producing some T4 of its own, if the overall NDT was lowered again, but then I guess not if the TSH is still suppressed.......

Nutrients were optimised as best as possible, iron always on the low side but in range at the time, and AM cortisol elevated a bit in line with T3 consumption I guess, but no I couldnt tolerate more, I felt absolutely dreadful until a bit more T4 went back in.

Thank you for your reply and I hope you are keeping well. Every best wish , G.

[greygoose in reply to Gillybean1]

No, the thyroid won't start producing anything much in the way of hormone until the TSH rises a bit. So, low/zero FT4 is perfectly normal on T3 only.

[arTistapple]

Great question and great answer from greygoose .

[helvella Administrator]

It appears some believe T4 is necessary for the brain. However it is very clear that some members have very sharp brains despite taking no T4 at all.

T4 has a role in the brain as well as T3

healthunlocked.com/thyroidu...

Like everything else, this need is likely individual with us being different in this as everything else.

[Gillybean1]

Hi Helvella,

Thank you for your reply. Yes and it looks like all the sharp brains can be found here on this forum!! thank goodness, not sure where I would be without all of you here,after a glut of bullying consultants.

Every best wish, G