Compare peptide purity across shops using third-party lab tests published on Peptigrity — with the spread of results (not just an average) and the measured quantity versus the label (how many mg the lab found in the vial), both computed from the lab database. No test can be paid for, hidden or removed.
Peptide purity is one of the most important quality indicators. Higher purity means fewer impurities, degradation products, and potential contaminants. Third-party lab testing by independent laboratories provides the most reliable purity data — more trustworthy than vendor-provided certificates.
But purity alone doesn't tell the whole story. Always check the test count. Eight tests all landing at 99%+ is far stronger evidence than a single test at 99.9% — which is why this tool sorts by test count, shows the spread and flags single-test brands.
HPLC separates a peptide sample into its individual components and measures the proportion that is the target peptide versus impurities. 99% purity means 99% of the sample is the target peptide.
| Purity range | Classification | Typical use case |
|---|---|---|
| ≥ 99% | Excellent | Quantitative research, sensitive assays |
| 98–98.9% | Research grade | General research applications |
| 95–97.9% | Marginal | Screening, preliminary research only |
| < 95% | Below standard | Not suitable for most applications |
The lab weighs what is in the vial and reports it next to the labelled amount. On most certificates that figure is gross mass — powder including counter-ion and water — not net peptide content, so it describes the vial's fill rather than its exact active content. Where a certificate states which basis it used, this page will say so; until then the number is shown as the certificate reports it.
Results are third-party certificates published by shops and collected from their official channels, verified community-submitted reports, and — as a pilot — tests Peptigrity commissions itself. Every test links to the original laboratory document. No test can be paid for, hidden or removed. To commission your own test, see how to get your peptides independently tested.