LindaRN_retired said:

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

Adding a me-too, because a thread of one person's experience is not much use. I had assumed I was the exception until I read this.

Dr.PeteFamMed said:

Say what you would expect to see if you were wrong, before you look.

That reframing is the part I needed.

From the other side of the consultation, briefly. It is worth asking what the claim would look like if it were false. If nothing would look different, it is not a claim about the world and no amount of discussion will settle it.

NurseAsh_DET said:

It is worth asking what the claim would look like if it were false.

Mine went the same way, slower.

Moderator note: the sourcing question belongs in the vendor section and has been split out. Thread quality here is what the rules are for. Keep it up.