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What Is a Certificate of Analysis (COA)? How to Read One

July 16, 2026 · 5 min read · The Vial Post Research Desk

A Certificate of Analysis (COA) is a lab document reporting a product batch's purity and identity. Learn what a peptide COA contains, how to read HPLC and mass-spec results, and how to verify one.


# What Is a Certificate of Analysis (COA)? How to Read One

Short answer: A Certificate of Analysis (COA) is a document from an independent laboratory that reports the results of quality testing on a specific production lot of a product — most importantly its purity and identity. For research peptides, a COA is the primary proof of what's actually in the vial.

> TL;DR — A COA = lab proof for one batch. Look for: the compound name, lot number, purity % by HPLC, identity by mass spec, the testing lab, and the date. No COA (or a COA for a different lot) = no verification.

Why a COA matters Anyone can print "99% pure" on a label. A COA is the evidence behind that claim, produced by an analytical laboratory testing an actual sample from the batch you're buying. In research, knowing the true purity and identity of a compound is essential — impurities or a misidentified compound invalidate results.

What's on a peptide COA A complete COA typically includes:

  • Product name and lot/batch number — the COA is only valid for that specific lot.
  • Purity (%) by HPLC — High-Performance Liquid Chromatography separates the sample; the target peptide should make up the stated percentage (e.g., ≥99%).
  • Identity by mass spectrometry — confirms the molecule's molecular weight matches the expected peptide, proving it's the right compound.
  • Test date and the name of the testing laboratory.
  • Sometimes additional screens (heavy metals, microbial, endotoxin) depending on the product.

How to read the two key results - HPLC chromatogram / purity value: A tall, clean main peak with minimal smaller peaks indicates high purity. The reported number (e.g., 99.2%) is the proportion of the sample that is the target peptide. - Mass spec (identity): The measured mass should match the peptide's known molecular weight. This is what confirms you have the compound the label says — not something else.

How to verify a COA A trustworthy COA is lot-specific and independently issued — not a generic marketing PDF. At Dynamite Research Peptides, product COAs link to third-party verification (Purity Analytics), so the result is traceable to the lab rather than self-reported.

Red flags - A COA that doesn't list a lot number. - The same COA reused across obviously different products. - Purity claimed on the label but no COA available at all. - A COA dated years before the batch you received.

Every applicable Dynamite Research Peptides product includes a batch Certificate of Analysis. All products are for in-vitro laboratory research use only — not for human or animal consumption.

Sourcing note

Researching this compound? See where to buy research peptides — what to look for in third-party testing, purity, and a Certificate of Analysis.

For research and educational use only. Not medical advice. Compounds discussed are for laboratory research use only and are not for human or veterinary consumption.