What Is a Certificate of Analysis?
A certificate of analysis (COA) is the document that tells you what is actually in the vial. In a market where claims are easy and verification is rare, it is the one piece of paper that separates a considered supplier from a hopeful one.
What a COA actually is
A certificate of analysis is a document produced by an independent, accredited laboratory after testing a batch of a compound. It records what was tested, the method used, and the result — typically purity (the percentage of the desired compound), identity (confirmation that the molecule is what the label says), and sometimes additional checks such as residual solvents or endotoxin.
The key word is independent. A supplier's own in-house testing is better than nothing, but a COA from an accredited third-party laboratory is the standard that matters, because the lab has no incentive to favour any particular result.
What to look for
When you read a COA, three things matter. First, the purity figure — for research peptides, ≥98% is the benchmark most researchers expect. Second, the batch number — it must match the batch number on the vial label, so you know the certificate actually corresponds to the vial in your hand. Third, the laboratory name and accreditation — a reputable, accredited lab is the whole point.
If any of those three are missing or do not match, the certificate is not doing its job. Every vial we ship carries a batch number on the label and a matching certificate in the box, and you can verify both on our batch verification page.
Why we ship one with every order
The peptide market includes suppliers who make purity claims without ever producing a certificate, and suppliers whose certificates do not match their labels. Shipping an independently verified COA with every vial — and making it verifiable online — is the simplest way to be held to our word.
It is also the cheapest insurance you have. Reading a COA is the single most useful habit a researcher can develop, and it takes under a minute once you know what to look for.
Every order is independently batch-verified and ships free Australia-wide.
Educational information only. Nothing here is medical advice or a therapeutic claim. Speak with a qualified healthcare professional before beginning any protocol. Last reviewed 23 June 2026.
Independent reading
Our library is calm, introductory wellness copy. When you want published-evidence summaries, tier rankings, and outcome guides written for researchers, reptides.co is a useful next step — entirely separate from Peptides Direct.
- Peptide tier list47 peptides ranked S–F by published human evidence — free to browse from the reptides homepage.reptides.co
- MethodologyHow tiers are set, how citations are audited, and how rankings change when trial data moves.reptides.co
- Weight lossEditorial guide to GLP-1 class peptides and related metabolic compounds.reptides.co
- Recovery & injuryHealing-category peptides — what the preclinical and clinical record actually shows.reptides.co
- Skin & anti-agingCopper peptides, blends, and cosmetic-category evidence in one place.reptides.co
- Growth hormone axisSecretagogues, GHRH analogs, and how the evidence stacks up.reptides.co
- Focus & cognitionNootropic peptides — trial history, mechanisms, and where the record is thin.reptides.co
- LongevityMitochondrial peptides, bioregulators, and what is still preclinical.reptides.co
- Peptide market mapSupply chain, testing, pricing context, and regulatory movement — updated quarterly.reptides.co
Independent third-party research on reptides.co — not affiliated with Peptides Direct. Research reference only, not medical advice.