Adding the numbers, since they settle part of this. Red flags, in rough order of how much they should worry you: no verifiable address, no batch numbers, prices far under market, vendor-commissioned tests only, pressure toward irreversible payment, and shipping with no temperature control.
I would rather be corrected than agreed with, if it comes to it.
One thing that is still open after Dr.PulmRoch’s answer:
How people are distinguishing a supplier having a bad batch from a supplier on the way out?
raj_cambridge said:Red flags, in rough order of how much they should worry you: no verifiable address, no batch numbers, prices far under market, vendor-commissioned…
There is a second half to this that has not been said yet. 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.
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Browse GL BiochemClosing the loop on my own question.
Went back through my own correspondence with an earlier supplier and the warning signs were all there in the replies, weeks before the quality changed. I was reading the product and not the behaviour.
traveltech_sara said:The useful checklist is about verifiability rather than presentation.
Right, and one flattering data point from a group buy is not consistency. Consistency means separate batches, separately commissioned, over months.