Can anyone please tell me the name of the Urine test that tests a resistance at a cellular level, for FT4 and FT3.

[Zuzka1]

Thank you - any help appreciated.

[jimh111]

The urine test does not measure cellular activity, this is a misapprehension that sometimes does the rounds. The urine test measures the amount of hormone extracted from the blood by the kidneys over a 24 hour period. It gives an approximation of blood hormone levels, averaged over a 24 hour period. For patients taking T3 medication the result is less dependent upon the timing of taking the blood.

[Zuzka1 in reply to jimh111]

Thank you for answering. How do I test if I have cellular resistance?

[diogenes Remembering]

If you have cellular resistance, then either or both FT4 and FT3 will be abnormally high in blood tests.

[Zuzka1 in reply to diogenes]

My last blood test on Thursday showed my FT 3 was double what the top of the range states it should be....

[Zuzka1 in reply to diogenes]

So what’s the procedure if that is the case for me?

[diogenes Remembering in reply to Zuzka1]

First check TSH to make sure you aren't hyperthyroid. Second, if you don't feel ill, then your resistance to T3/T4 is known and should be archived so you don't get inappropriate treatment in future.

[Zuzka1 in reply to diogenes]

Ok my TSH is still really oppressed. 0.0025 (0.400-3.100)

My FT4 is mid range. 12.5 (9.0-29.0)My FT3 is high. 8.2 (2.9-4.9)

I have Hashimotos.

What would you say the next step is?

I don’t feel I’ll. I feel the best I’ve felt really for 2.5 years...

[diogenes Remembering]

The usual FT3 range is about 3.2-7. The range you quote is extremely low at the upper part of its range and I suspect it is faulty. I don't know what therapy you are on but if it includes T3, only a modest decrease might get you into what I think is a sensible normal range. Its a matter of trying out very minor changes in therapy and see what happens.

[Zuzka1 in reply to diogenes]

Ok I’ve decreased by a 1/4 of my T3 tablet.

I am in France...might be why my ranges are different?

My Endo thinks I’m on 1x Eurythal plus 75mcg Levo.

I’m actually taking 1x Eurythal plus 1 and a 1/4 T3 now. I just dropped a 1/4 6 days ago.

I can feel my drop in ‘mojo’ already....

I want to stay on the higher dose but....I see my Endo again on the 9th. I think she might flip out about my T3....

[jimh111 in reply to Zuzka1]

If you are taking just one quarter of an L-T3 tablet (Tiromel?) then your fT3 shouldn't be so high. Did you have the blood taken just after taking the tablet?

[Zuzka1 in reply to jimh111]

I’m taking 1x Eurythal plus 1 and a 1/4 T3

[Zuzka1 in reply to jimh111]

Sorry...I took tablets at 10pm and bloods at 9am

[jimh111]

OK. I see. If you need this dose then fine. It is 'supraphysiological', in simple terms more than a healthy person needs. It suggests a form of resistance but there's no teat to measure this. I'd stay on this dose if this is what you need but keep an eye on your heart rate and every so often see if you are OK on a slightly lower dose.

[Zuzka1 in reply to jimh111]

Ok I think this is what I’m going to do.

I see my Endo in 9 days. I’m going to tell her I took my tablets much later in the night. I’ve dropped a 1/4 dose of the T3, she will re test me and it will be lower because I also won’t take my tablets untill after the bloods are taken.

Then I’m going to up my dose by a 1/4 again. For the first time forever I actually wanted to excercise. I lost weight for 3 weeks in a row. I am ketogenic.

As soon as I dropped I gained 2lbs...my mojo has gone. It’s depressing trying to feel well for so long....then having to drop dose again.

I wear a Fitbit all the time so can see my heart.

Being ‘over’ the range...is it ‘bad’ for me? Or do I just totally go on how I feel?

Thank you for helping.

[jimh111 in reply to Zuzka1]

Ultimately you have to go by your response to treatment, symptoms do not always follow the blood test! However, when you have these higher doses it makes sense to take a little more care.