QSC sent wrong product — need advice

InsuranceTom said:

The pattern that distinguishes a bad batch from an exit is behaviour rather than product.

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.

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

VanRx_Mike said:

Eight months with one supplier, then a change in how they communicate that I noticed before I noticed anything about the product.

Vendor reputation tracking for vendor vetting: I maintain a personal spreadsheet with every order I've placed — date, vendor, batch number, Janoshik result, personal efficacy assessment (1-5 scale), and any issues.

After 15 orders across 3 vendors: average purity 98.7%, zero sterility concerns, 1 shipping issues (all resolved). This data gives me confidence in my current source and documentation if issues arise.

I encourage everyone to track their orders systematically. Community data aggregation makes us all safer.

TrialNerd_Beth said:

I disagree that testing history is decisive.

Adding the part of the answer the thread has not reached. 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.

Following on from oliver_london — and this may be the naive question:

What a vetting checklist should actually contain, as opposed to a list of things that are easy to fake?

OP back with an update, since a thread like this is useless without one.

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.