This gets cited here weekly, usually second-hand, so it is worth setting out what it does and does not establish.
Prices dramatically below market are the strongest single signal, and the reason is arithmetic rather than suspicion. Synthesis, testing, and cold-chain shipping have floors. A price well under the floor means something was skipped, and the two things that get skipped are testing and content.
Where I think it is weakest: the completion rate deserves as much attention as the headline, because a large effect among those who finished is a different claim from a large effect among those enrolled.
What would genuinely help is knowing what a vetting checklist should actually contain, as opposed to a list of things that are easy to fake. Tell me what I have not thought of.
Figures above are from the primary publication rather than the press summary. If a number here disagrees with one you have, post yours and we will work out which of us is reading a secondary source.
tommy_boulder said:Prices dramatically below market are the strongest single signal, and the reason is arithmetic rather than suspicion.
That is correct as far as it goes, and here is where it stops going. The pattern that distinguishes a bad batch from an exit is behaviour rather than product. A bad batch comes with communication, a reshipment offer and a batch number. An exit comes with slower replies, pressure toward less reversible payment methods, sudden discounting, and the same reassurance repeated without any new information. The product tells you less than the correspondence does.
tommy_boulder said:Prices dramatically below market are the strongest single signal, and the reason is arithmetic rather than suspicion.
I disagree that testing history is decisive. It tells you what a supplier did when they were being watched. Continuity of behaviour under stress — a late shipment, a failed test, a complaint — is more predictive than any run of good results.
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Shop Reference StandardsShort answer first, then the reasoning. The useful checklist is about verifiability rather than presentation. Independent test results commissioned by buyers rather than by the seller, consistency across multiple batches over time rather than one flattering report, a physical address and a company registration that resolve, batch and lot numbers on the actual labelling, and a shipping practice that matches what the material needs. Everything a good-looking website provides is cheap to fake; none of the items above are.
Dr.ReproEndo said:The pattern that distinguishes a bad batch from an exit is behaviour rather than product.
Same experience, arrived at from the opposite direction. Nothing to add that would improve it.