Clinical perspective, offered as context rather than as advice. The useful move here is to separate what is established from what is widely repeated. Those two sets overlap less than the confident tone of most write-ups suggests, and the second set is where nearly all the disagreement on this board comes from.

Ask again with the specifics and you will get a better answer than this one.

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.

Worth separating that from the trial evidence, which this thread keeps folding into the same question. They behave differently and the advice does not transfer.

One thing that is still open after HPLC_Greg’s answer:

How would you tell the difference between that and the alternative explanation?

PeptideChemSF said:

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…

This is where I part company with the consensus forming above. Pushing back on the anecdote-stacking. Twenty people reporting the same thing is twenty samples from the same self-selected pool, not twenty independent confirmations.

Moderator note: leaving this open. It is being argued well and the disagreement is the useful part.