Update
What a certificate of analysis actually proves
A COA is a lab report on a sample, commissioned by the seller. That is worth something, and it is worth considerably less than it is usually taken to mean.
Almost every vendor in this market publishes certificates of analysis, and almost every buyer treats them as the answer to whether a vial contains what the label says. They are evidence, and understanding their limits is the difference between using them well and being reassured by them.
A certificate reports what a laboratory found in a sample it was given. Four gaps follow from that sentence. The sample was selected by whoever commissioned the test, and it is not your vial. The laboratory was chosen and paid by the seller. Purity by mass spectrometry says what fraction of the material is the target compound, not whether the remainder is inert. And a certificate is a snapshot of a batch at a point in time, before shipping, storage and whatever happened in between.
None of that makes them worthless. A vendor who publishes them consistently — names the testing lab — and dates them per batch is telling you something real about how they operate. A vendor who publishes none is telling you something too.
What to check, in order: does the certificate name the batch, and does that batch match your vial; is the testing laboratory named and independent of the seller; is there a date; and does the report show the actual chromatogram rather than only a summary figure. A PDF with a purity percentage, no lab name and no date is a graphic, not a test.
We record whether a vendor publishes batch numbers in the directory, because that is a checkable fact about their process, not a claim about their product. We do not verify anybody's certificates and we do not test vials, and the directory says so.
This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on Bioalmanac is medical advice.