How to Read a Certificate of Analysis (COA)
Last updated: July 1, 2026 · For laboratory research use only.
A certificate of analysis (COA) is the document that turns a claim into evidence. For a research peptide it should answer two questions independently: is this the compound the label says, and how pure is this specific batch. This guide explains how to read one — using the real, published reports linked from our product pages as worked examples.
What a COA actually is
A COA is a laboratory's written result for one specific lot of material. It is not marketing and not a self-declaration: a credible COA names the lab that ran the test, thebatch it applies to, the date of analysis, themethod used, and a result. If any of those are missing, you are reading a label, not a certificate.
Every Ouralus product that has been tested publishes its COA as plain text on the product page — lab, batch, analysis date, assayed purity, and a unique verify key — with the full report PDF linked. See how we verify for the standard behind it.
HPLC identity — “is it the right molecule?”
HPLC (high-performance liquid chromatography) separates the contents of a sample as they pass through a column, producing a chromatogram — a trace of peaks. Identity is confirmed by comparing the sample's retention behaviour against a reference for the named compound. In practice: the lab is checking that the main peak is where the target peptide should be, not a different molecule sold under the right name.
Purity (assay) — “how much of the batch is the compound?”
Purity is the quantified share of the sample that is the target compound, with related substances resolved and measured. On an HPLC assay it is typically reported as a percentage — for example 99.4% — meaning that share of the measured material is the named peptide, by that method. A higher, independently measured figure means fewer unresolved related substances in that lot. Purity is always a property of a specific batch, which is why it is tied to a batch number and date.
The anatomy of a Janoshik COA
Independent reports from Janoshik (the lab we use) carry these fields. Read them in this order:
| Field | What it means |
|---|---|
| Lab | The independent laboratory that ran the analysis (Janoshik). The vendor did not test its own material. |
| Product / batch | The named compound and the exact lot the result applies to. Purity only describes this batch. |
| Analysis date | When the batch was tested. A COA should correspond to the lot you are actually receiving. |
| Method | HPLC for identity and purity. Ouralus reports identity and purity by HPLC only. |
| Assayed purity | The measured purity percentage for the batch, as printed by the lab. |
| Verify key | A unique code that lets anyone confirm the report directly with the lab — the part that makes it independently checkable. |
A worked example
Two real reports currently published on our product pages, read field by field:
| Field | Retatrutide | GHK-Cu |
|---|---|---|
| Lab | Janoshik | Janoshik |
| Batch | white cap | Blue Cap |
| Analysis date | 2025-11-07 | 2025-11-25 |
| Assayed purity (HPLC) | 99.499% | 99.794% |
| Verify key | SKYPD9CJHB21 | 7JSHIUYUC714 |
You can open these on the Retatrutide and GHK-Cu pages, where the same figures appear in the COA card alongside the linked report PDF.
How to verify a report key
The verify key is what separates a checkable certificate from a printed number. To confirm one:
- Note the verify key on the product page (or on the report PDF).
- Go to janoshik.com/verify.
- Enter the key. The lab returns the report it issued for that batch — you are reading it from the lab, not from us.
- Check that the compound, batch, and purity match what the product page shows.
If a supplier shows a purity number but no way to confirm it with the issuing lab, treat the number as unverified. Our companion guide, How to Verify Research Peptide Purity, covers the red flags in full.
What a COA does not tell you
A COA is scoped to what was measured. An HPLC identity-and-purity report does not, by itself, establish heavy-metal content, microbial or endotoxin levels, or anything about safety or use. Ouralus reports HPLC identity and purity only and does not claim heavy-metal, microbial, or endotoxin testing. A COA also says nothing about how a material may be used — it is a measurement of the material as supplied.
Research use only. Ouralus materials are supplied strictly for laboratory research use. They are not drugs, supplements, foods, or medical devices, and are not for human or animal consumption. A certificate of analysis characterises the material as tested; it is not a statement that any material is safe or suitable for any use.