Accepted answer
The part that matters: the certificate is not the answer to your question; it is a data point that you need to combine with other information to build an answer.
The test date matters because a certificate six months older than the vial is not evidence about your material, it is evidence about what the material was like half a year ago.
Put another way, test results from a material supplier are different from independent results in ways that matter for interpretation, even if both are accurate.
Pharmacopoeial standards require method validation steps that research-grade certificates almost never claim to meet, and the absence of that claim is itself information.
Worth noting that none of this is medical advice, and a compound sold for research use carries no regulatory approval in any jurisdiction.
If the certificate does not trace to your vial, it is not evidence about your vial.
For what it is worth, my own result was within half a per cent of this. – bea_castellanos 8 days ago Any reason this would differ for a longer peptide? – dmitri_savchuk 9 months ago add a comment