Re: Lab ???
No, it isn't T3 uptake... which amazingly, has nothing to do with your T3 levels.
Look for any of these terms ~
free T3 - or - T3, free
triiodothyronine, free - or - free triiodothyronine
If none of those is listed, some labs have an "Other" blank, where it can be written in.
A few labs don't even run the test, in which case, you'll have to go elsewhere to have it done.