A certificate of analysis is the only document that tells you what is actually in a vial. The label tells you what the supplier says is in it. The certificate tells you what an independent laboratory measured. If you buy research peptides in the UK and you have never read one properly, this guide walks through a real Janoshik Analytical report section by section.
What a certificate is, and what it is not
A certificate of analysis (COA) is a report issued by a testing laboratory for one specific lot of material. It lists the tests performed, the method used for each, the result, and the specification the result was judged against. It is lot-specific: a certificate for lot 2609 says nothing about lot 2610.
It is not a general quality statement, not a safety document, and not proof that the vial in your hand came from that lot unless the lot number on the label matches the lot number on the report. That match is the whole point of the system, and it is the first thing to check.
The header: who tested what, and when
The top of a Janoshik report carries four things worth reading:
- Test number. Janoshik gives every analysis a unique number, for example #152765. That number appears in the report’s URL on verify.janoshik.com, which is how you check the document at source rather than trusting a PDF someone emailed you.
- Sample description. The compound name and fill as submitted, for example “LP3-R 10 mg”. Note that this is the name the client gave; the analysis confirms whether the material matches it.
- Client. The company that submitted the sample. If a supplier shows you a certificate where the client is a different company, the certificate belongs to someone else’s lot.
- Date of analysis. Certificates do not expire in a formal sense, but a lot tested eighteen months ago may not be the lot currently shipping.
Purity by HPLC
High-performance liquid chromatography is the purity test. The sample is dissolved and pumped through a column that separates it into its components; a detector records each component as a peak on a chromatogram. The area under the main peak, as a percentage of the total area of all peaks, is the purity figure.
A specification of 99% means at least 99% of the material detected is the named compound. The remaining fraction is related substances: truncated sequences, deletion sequences, oxidised variants and other by-products of synthesis. On a good report you will see the chromatogram itself, with the main peak and any minor peaks labelled with their retention times and areas.
Two things people get wrong here. First, purity is a percentage of what the detector sees, not of the vial’s mass; water, counter-ions and salts are handled by other tests. Second, a purity figure without a chromatogram is a number with no evidence behind it. Janoshik reports include the chromatogram.
Identity by mass spectrometry
Purity tells you the sample is mostly one thing. It does not tell you what that thing is. A vial of 99% pure oxytocin would pass an HPLC purity test even if it were labelled BPC-157.
Identity is confirmed by mass spectrometry. The instrument measures the mass-to-charge ratio of the molecule and its fragments, and the report compares the observed molecular weight with the theoretical molecular weight of the labelled compound. For BPC-157 that theoretical figure is about 1,419.5 g/mol; for LP3-R about 4,731.5 g/mol. A match within the instrument’s tolerance confirms the material is the compound on the label.
This is the test that separates a supplier who sells what they say they sell from one who does not. Always look for it.
The other lines you may see
Depending on what the client requested, a certificate may also report:
- Appearance. Usually “white to off-white lyophilised powder”. GHK-Cu is the exception; its copper complex is blue.
- Water content (Karl Fischer titration). Residual moisture in the freeze-dried powder, as a percentage. Lower is better for stability.
- Endotoxin (LAL assay). Bacterial endotoxin, reported in endotoxin units per milligram.
- Peptide content / net peptide. The proportion of the powder’s mass that is peptide rather than water and counter-ion. This is a different number from purity and is sometimes confused with it.
If a line is absent, the test was not run. That is not necessarily a problem, but it means the certificate makes no claim about it.
Matching the certificate to the vial
The lot number on the vial label must match the lot number on the report. On BluePeak vials the lot number is printed on the label below the catalogue reference. If a supplier cannot tell you which lot your vial came from, or shows you a certificate with no lot number, you have no way of connecting the document to the product.
Verifying at source
The most reliable way to read a Janoshik certificate is not to read the PDF at all but to open the record on Janoshik’s own site. Every BluePeak product page with a published record has a “Verify on Janoshik” link that opens the test on verify.janoshik.com. If the test number on the PDF does not open a matching record there, treat the PDF as unverified.
A short checklist
- Lot number on the vial matches the lot number on the certificate.
- Client name is the supplier you bought from.
- HPLC purity is stated with a chromatogram, and meets the supplier’s specification.
- Mass spectrometry identity is reported and matches the theoretical molecular weight.
- The test number opens a matching record on the laboratory’s verification site.
Five checks, two minutes. Every BluePeak certificate is designed to pass all five, and the Certificates of Analysis page lists the published records for the lots currently shipping.
BluePeak Peptides supplies research peptides for laboratory use only. Nothing in this article is guidance for use of any kind.
