That may not be so... I am hypothyroid so I like to think I know a little bit.
"T3 Resin Uptake or Thyroid Uptake. (T3RU) This is a test that confuses doctors, nurses, and patients. First, this is not a thyroid test, but a test on the proteins that carry thyroid around in your blood stream. Not only that, a high test number may indicate a low level of the protein! The method of reporting varies from lab to lab. The proper use of the test is to compute the free thyroxine index."
What you really need to get is "Free T3" tested. That is really the only definitive test there is to determine how much T3 is in your system.
When you add alien compounds to the body it reacts... Kind of like how when Test or DNP is taken "Total" thyroid numbers will drop *but* the amount of "Free" thyroid hormones will stay the same.