Sharing this as a documentation experience, not a health claim. Ordered a research vial from one of the verified vendors here. The batch COA they emailed referenced lot A-2291 but the vial sticker read A-2288. Purity numbers on the sheet looked fine on paper, but a sheet for a different lot tells you nothing about what is actually in your vial.
I emailed support with photos of both. To their credit they responded within a day, said it was a fulfillment mix-up where an older lot got picked, and sent the correct COA for A-2288 plus offered a replacement. The corrected sheet matched the vial.
My takeaway is narrow: always check the lot on the vial against the lot on the COA before anything else, because a real COA for the wrong batch is easy to miss. I am not making any claim about quality or what the contents do. If purity actually matters to you for a given use, independent third-party testing is the only thing that settles it, and a professional should be involved in any decision that touches your health.