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.