Why the COA matters
The research peptide market is not regulated. A vial labeled "BPC-157 5mg" can contain the right peptide, a lower-purity version, incomplete sequences, or, in the worst case, a different molecule entirely. A COA closes that gap with documented lab evidence.
HPLC purity
HPLC (High-Performance Liquid Chromatography) is the standard method for measuring purity. The result is a percentage of target peptide in the sample. For research, look for at least 98%, while higher-quality peptides reach ≥99%. A solid COA includes the chromatogram itself.
Mass spectrometry (MS)
HPLC tells you purity; MS tells you identity. It measures molecular weight to the decimal and compares it to the theoretical value. For BPC-157 that is around 1,419.5 Da. Without MS data, a COA does not prove the peptide's identity, so don't accept purity numbers alone.
Red flags in a COA
Things to watch for: a generic COA without a batch number, in-house testing only with no independent lab, missing chromatogram, no mass spectrometry, or an old analysis date. Peptid.si publishes every COA with independent third-party testing in the COA Vault.
References / Links
- Zolner WJ (2012). Why do I need a Certificate of Analysis? Int J Pharm Compd. PubMed
- Allen LV Jr (2012). Quality control analytical methods: Certificates of Analysis, Part 1. Int J Pharm Compd. PubMed
- Whitmire ML, Bryan P, Henry TR, Holbrook J, et al. (2010). NonClinical Dose Formulation Analysis Method Validation and Sample Analysis. AAPS J. PubMed
- Mant CT, Chen Y, Yan Z, Popa TV, et al. (2007). HPLC analysis and purification of peptides. Methods Mol Biol. PubMed
- Pawar R, Tivari S, Panchani D, Makasana J (2024). A stability-indicating method development and validation for the determination of related substances in novel synthetic decapeptide by HPLC. J Pept Sci. Wiley
