How to read a peptide COA
A certificate of analysis (COA) is a laboratory's report on one tested sample. It can tell you a lot about that sample. This guide covers what to check, what a COA cannot establish, and how VialTalk publishes vendor COAs.
Research information only; not for human use.
What a peptide COA reports
A COA records which laboratory tested a sample, when, by which methods, and what it found. For research peptides it usually covers:
- Identity — whether the sample is the compound named. Mass spectrometry (for example LC-MS) confirms molecular identity directly; an HPLC retention time on its own is weaker evidence.
- Purity — the share of the sample that is the target compound, usually measured by HPLC.
- Quantity — how much compound the vial held compared with the amount on its label.
- Add-on tests, when run — endotoxin, heavy metals (ICP-MS), sterility, and batch conformity across several vials from the same batch.
What to check on any COA
- The lab — a named, independent third-party lab. Where the lab offers a verification code, link or QR code, checking the report on the lab's own site is stronger than the PDF alone.
- Sample identification — the compound, the labeled amount, and a batch or lot number you can match to the product listed.
- Test date — and whether the tested batch is the one currently being sold.
- Methods — which method produced each result. A purity figure without identity confirmation answers a different question.
- Quantity against the label — a vial labeled 10 mg that tested at 8 mg holds less than its listing suggests, which matters when comparing price per mg.
- What was not tested — a missing endotoxin or sterility result means it was not reported, not that it passed.
What a COA does not establish
- Other batches — a COA covers the sample tested. Other batches, and other vials of the same batch unless batch conformity was tested, can differ.
- Handling after testing — it says nothing about how a product was stored or shipped after the test.
- Safety or approval — it is not evidence of safety or effectiveness in people and is not regulatory approval. Research peptides are not approved for human use.
- The vendor as a business — lab results do not describe shipping, communication or service. Community vendor reviews cover those.
How VialTalk publishes vendor COAs
Every COA on VialTalk must come from a third-party testing laboratory; in-house testing is not accepted. Staff review each submission before it is published. Published COAs are scored for the depth of testing and the strength of the results, and every approved COA is scored the same way regardless of the vendor's plan. Paid placement never changes a COA grade.
Recalled reports stay visible on the vendor's profile as safety notices, and superseded reports are kept as history rather than deleted.
Each vendor profile lists its published COA reports, and price listings show how many test panels the matching COA covers.
See COAs alongside reviews and prices
Vendor profiles bring together each vendor's published COA reports, community reviews and current research listings.