Testing RT3 while on T3 only

[silverequus]

I just had lab work done and wanted to add in the reverse T3 serum test, because I've found T3 only to work well for my hypothyroidism. The test result was "below low normal". Since I am taking T3 only, does anybody know if that could that give a low RT3 result, and not accurately show whether I actually have an RT3 problem? From what I've read, below range RT3 levels are rare.

[pennyannie]

Hello Silverequus

Reverse T3 is actually surplus unconverted T4 - so seeing as you are only taking T3 thyroid hormone replacement this is quite possible and nothing to worry about .

I see you are diagnosed Hashimoto's AI thyroid disease so your thyroid is failing on producing sufficient thyroid hormones to keep you well.

T4 is inert and basically a storage hormone waiting to be converted by your body into T3 the active hormone that runs all your bodily functions.

You can live without T4 but you can't live without T3 :

[silverequus in reply to pennyannie]

Thank you, that's what I was wondering about. I thought maybe my thyroid might still be producing some of its own T4, but free T4 levels are also extremely low on the labwork, so it does t seem to be doing much.

[tattybogle]

RT3 can only be made from T4 ... if you don't take any T4 and if your thyroid isn't producing much T4 , then there is nothing much to make rT3 from.

Your body simply can't make rT3 from T3 ...

so i assume a low / below range rT3 is to be expected in most 'T3 only' patients.

//

[silverequus in reply to tattybogle]

Thank you, that makes sense!