How to Read a COA

A Certificate of Analysis (COA) documents batch-specific test results for a research peptide. This guide explains common sections so buyers can review documents systematically — not accept marketing summaries at face value.

What a COA is — and is not

A COA is a batch-specific analytical record. It is not a regulatory approval, GMP certificate, or platform endorsement. Peptide From China does not issue supplier COAs.

For laboratory accreditation review, see How to Verify a Laboratory.

Common COA sections

Product identification

  • Peptide name and one-letter or three-letter sequence
  • CAS or internal catalog reference (when used)
  • Salt form or modifications (acetate, DAC, etc.)
  • Batch or lot number

Specification and results

  • Appearance (for example lyophilized powder)
  • Net peptide content or amount per vial
  • HPLC purity (area percent of main peak)
  • LC-MS molecular weight or m/z confirmation
  • Water content or residual solvents (when listed)

Method transparency

  • Analytical technique (HPLC, LC-MS, etc.)
  • Column type and detection wavelength
  • Integration or calculation basis for purity
  • Instrument or method reference number

Traceability

  • Manufacturing or release date
  • Testing laboratory name and address
  • Analyst or quality unit signature
  • Storage guidance (when provided)

Practical review tips

  • Treat the COA as a batch-specific document — not a generic marketing sheet.
  • Compare batch numbers on vials, invoices, packing lists, and the COA before releasing payment.
  • Request method details when only a purity percentage is shown.
  • For new suppliers or complex sequences, plan for HPLC plus LC-MS on the same batch.
  • Retain a sample for independent retesting if results are critical to your program.

For laboratory research and analytical use only. Not for human consumption. Not intended to diagnose, treat, cure, or prevent any disease.