PharmD_Rodriguez said:

It helps to ask what evidence would change your mind before you look at any.

I read this differently from PharmD_Rodriguez, on substance rather than tone. 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.

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.

KevinCompounds said:

Twenty people reporting the same thing is twenty samples from the same self-selected pool, not twenty independent confirmations.

Adding the part of the answer the thread has not reached. 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.

Following on from PedsEndoPhilly — and this may be the naive question:

Was that from a primary source or from a summary of one?

Reporting back.

Update, and it is the boring outcome: nothing was wrong. The measurement I was reading had moved less than its own week-to-week variation, which somebody said upthread and I did not believe.