Dr.KarenChen said:

Prices dramatically below market are the strongest single signal, and the reason is arithmetic rather than suspicion.

This answered a question I did not know how to ask. Adding it to my notes with a link back to this thread.

Adding the clinical framing, because it changes how the question reads. 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.

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

Dr.EndoIndy said:

Vendor reputation tracking for vendor vetting: I maintain a personal spreadsheet with every order I've placed — date, vendor, batch number, Janoshik…

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. Not convinced. The evidence being cited is consistent with the conclusion and also consistent with two other conclusions nobody has ruled out.

Happy to go further on any of that.

One concrete data point for the thread. If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way. Most of the apparent contradictions in these threads dissolve at that step.

Moderator note: a post naming a supplier has been edited. Discuss suppliers in the review sections, not here.