DanielChem_CHI said:

Thyroid cancer screening labs for thyroid monitoring — addressing the boxed warning concern with actual data: Calcitonin level: 2.0 pg/mL (normal…

This is where I part company with the consensus forming above. The counter-case has not been addressed. Somebody upthread described the situation that does not fit, and the thread moved on rather than engaging with it, which is the failure mode this board is supposed to avoid.

Adding the numbers, since they settle part of this. The boring version of this is the one that works, and the boring version is: measure a baseline, change one variable, wait, measure again under the same conditions. Nobody wants that answer and it is still the answer.

VendorMark said:

Somebody upthread described the situation that does not fit, and the thread moved on rather than engaging with it, which is the failure mode this…

There is a second half to this that has not been said yet. The version of this that has an answer is narrower than the version being asked. Narrow it and it becomes tractable; leave it broad and the thread will produce nine confident and incompatible replies.

One thing that is still open after Dr.PainCLE’s answer:

What did you change at the same time, and can you separate the two now?

OP back with an update, since a thread like this is useless without one.

Reporting back for the archive rather than for the thread: I did the narrow version of what was suggested, gave it the full interval, and it settled. Posting it because threads without a follow-up are half a thread.