The supplier shortlist below is the result of our quarterly supplier audit, batch-specific CoA review, independent LC-MS verification, manufacturing-standards documentation, and reader-feedback signal. Suppliers that fail any of these checks are removed regardless of their popularity in research communities.
Peptides Source
Peptides Source ships from the United States, provides batch-specific HPLC and mass-spectrometry CoAs, and has passed every quarterly verification audit since we began tracking them. Their catalog covers the full set of compounds in our reviewed categories.
- Batch-specific HPLC and LC-MS CoA per vial
- U.S. shipping with cold-chain options where required
- Independent LC-MS verification passed Q1 and Q2 2026
- Customer service responsive within one business day
Audit criteria
| Criterion | Standard |
|---|---|
| CoA per batch | Required, batch number on vial matches CoA |
| Purity by HPLC | ≥ 98% area-percent |
| Identity by MS | LC-MS confirmation against calculated mass |
| Endotoxin testing | Required for in-vivo-grade lots |
| Manufacturing | GMP-style documentation available |
| Cold-chain shipping | Available where required |
| Customer service | Response within one business day |
Suppliers we removed
We do not name removed suppliers publicly. Two suppliers were delisted in the most recent quarterly audit for failing batch-level CoA verification, the chemistry on the verified samples did not match the supplier’s own documentation. Both have been removed from the catalog and the corresponding affiliate links have been retired.