A COA — Certificate of Analysis — is a document from a testing laboratory that reports what is actually in a batch. In an unregulated market, it is your single best tool for trust.
- ✦Identity — is it actually the peptide it claims to be?
- ✦Purity — what % is the real compound vs impurities? (98–99% is typical of good sources)
- ✦The lab — independent labs test batches; they publish and share results
Trustworthy sources test every batch, share the COA when asked, and stand behind the product. That after-market testing is exactly what you pay a good supplier for.
If a source cannot or will not show you a COA, that is your answer. The trusted list on this site exists because those vendors do the testing the gray market rarely forces.
✦ Key takeaway
In a market with no regulation, the COA is the closest thing to a guarantee. A vendor without one is a vendor making you gamble.