# How to read a peptide certificate of analysis

A practical framework for evaluating a peptide COA: lot identity, methods, results, dates, and unanswered questions.

By Drop Peptides editorial desk. Published 2026-11-13.
Canonical: https://droppeptides.com/journal/reading-a-coa

## At a glance

A certificate of analysis describes a particular sample and the tests reported for it. Start by matching the material and lot, then examine the methods, units, and limits of the report.

## Match the report to the material

Record the supplier name, material identifier, lot number, report number, and issue date. Compare those identifiers with the container and purchase record. A report for another lot is background information, not documentation of the material in hand. If a report is reproduced by a reseller, request the original source and preserve both versions.

## Separate the questions being answered

Identity, chromatographic purity, content, water, residual solvents, and other attributes describe different aspects of a material. Read which tests were actually performed. An assay result should include a method and units; a percentage without that context is incomplete. A result for one attribute does not answer an untested question.

## Record what the report does not establish

A COA does not by itself establish suitability for a particular experiment or authorize human use. Ask qualified laboratory personnel to evaluate the study requirements and any missing information. Retain the report with the corresponding safety data sheet and laboratory material record. Drop has not published verified supplier COAs for its sample catalog.

## Sources

- [OSHA: Hazard Communication and safety data sheets](https://www.osha.gov/hazcom)

## Related guides

- [Purity, identity, and content ask different questions](https://droppeptides.com/journal/purity-vs-identity)
- [COA vs SDS: two records with different purposes](https://droppeptides.com/journal/coa-vs-sds)
- [Building a traceable laboratory material record](https://droppeptides.com/journal/material-records)

For in vitro and laboratory research only. Not for human or veterinary use, administration, or consumption. Educational procurement context only, not medical or handling guidance.