Clinical perspective, offered as context rather than as advice. Take it one variable at a time. Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent argument can untangle them after the fact.

FDA_TrackerJim 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 answered a question I did not know how to ask.

Clinical perspective, offered as context rather than as advice. The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either. Those three things can all be true at once, and most arguments here are two people holding different parts of that.

Dr.Martinez said:

The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either.

This is my experience too, for whatever a second data point is worth. Posting only so the count is not one.

Moderator note: good thread. Keeping it here rather than moving it, because the question is general enough to be useful.