Check a Janoshik CoA: Verify Peptide Analysis Certificates in One Click
How to correctly read a Janoshik certificate of analysis (CoA) for research peptides and verify it in the lab database. HPLC, MS and the one-click verify link explained.
"Janoshik tested" appears on many peptide shops. But a lab logo on a product page and a certificate sent along as an image are not proof: both can be faked. What matters is whether you can find the test yourself in the lab's original database. This guide shows you how to read a Janoshik certificate of analysis (CoA) and verify it in one click, and why this is the most important step when buying peptides.
The key points at a glance
What it is about: A CoA is only worth as much as it is verifiable. HPLC + MS: Purity and identity are the two core values of any serious CoA. The test: The batch on the vial must match the batch on the CoA. One-click verify: At PeptidesDirect, every CoA entry leads directly into the Janoshik database via a button.
Who is Janoshik?
Janoshik Analytical is one of the most established independent third-party labs for analyzing research peptides and other substances. "Third-party lab" means: the lab is neither manufacturer nor seller, but an independent testing authority. That is exactly what makes a Janoshik CoA more valuable than a manufacturer's in-house analysis, provided you can verify the authenticity of the report.
The two core values on every CoA
HPLC purity
High Performance Liquid Chromatography separates the components of a sample. The purity value (e.g. 99.1%) indicates which share of the detected peptide species is the target peptide, that is, the area of the target peak relative to the total area of all peaks. It is a measure of chromatographic purity, not of the mass fraction in the vial: water, salts/counterions and residual solvents do not count toward it (the actual peptide content is reported separately as "content"). Research grade is usually at least 98%, with 95% often regarded as the lower limit. Several large side peaks point to impurities or degradation.
Mass spectrometry (identity)
MS confirms that the measured molecular weight matches the expected mass of the peptide, a strong indication that the correct compound is present. A deviation signals an identity or composition problem (e.g. a missing or wrong residue, an impurity, oxidation or a salt adduct). Important: a matching mass confirms the molecular weight, but not the exact amino acid sequence, since different sequences can have the same mass. Only tandem MS (MS/MS) verifies the full sequence.
Match the batch number
Purity and identity always apply to a specific batch. The batch number on the vial label should be linkable to the CoA, directly or via a verifiable test ID such as a Janoshik verify link. A generic CoA without a batch reference cannot be traced back to your specific shipment and serves more as general product information than as proof for exactly that batch.
The most common trap: the PDF without a source
By far the most common mistake is taking a CoA sent along as a PDF or photo at face value. An image can be edited, a logo copied, a purity figure changed. Without a comparison against the lab's database, a CoA remains an unproven claim.
Verify in one click
This is where our approach comes in. At PeptidesDirect, every batch ships with a third-party CoA, most commonly Janoshik, and every available certificate is backed by a "Verify on Janoshik" button. You will find this button in two places:
- on our Lab Reports page (/coa), which bundles all analysis certificates across all products, and
- directly on every product page next to the respective CoA.
One click takes you into the Janoshik database to exactly this test. There you see purity and identity at the source, independent of any PDF we show you. Currently every one of our Janoshik analysis certificates is backed by such a verify link.
Why we do it this way
Trust should not rest on our word, but on a source you can check yourself. Instead of just showing you a logo, we give you the direct path into the lab database. That is the difference between "Janoshik tested" as a marketing phrase and as a verifiable fact.
An honest perspective: what a CoA can and cannot do
Limits of what it tells you
A CoA confirms the purity and identity of the tested sample at the time of testing. It is not a guarantee of biological effect, not a sterility certificate and not an approval. We do not test the peptides ourselves and do not commission the tests in our own name: the CoAs come from the manufacturer and are produced by Janoshik as an independent third-party lab. We do not give our own quality guarantee, but instead make the available third-party lab evidence transparent and verifiable.
This sober framing is intentional. A demanding research audience recognizes exaggerated promises immediately. What counts is traceable transparency: a genuine third-party lab test per batch and a way to check it yourself.
Checklist for buying peptides
Before you buy research peptides anywhere, go through these points:
- Is there a batch-specific CoA at all, or just a general lab logo?
- Does the CoA report both HPLC purity and MS identity?
- Does the batch number on the CoA match the one on the vial?
- Can the test be verified in the lab database, or is it just a PDF?
- Is the supplier based in the EU? Within the EU single market, customs and import VAT do not apply, and the routes are on average shorter than with overseas suppliers (recipients outside the EU customs/VAT zone, such as the UK, Switzerland or special territories like the Canary Islands, may still face import charges).
If a shop has to pass on point 4, the most important stage is missing. What an EU alternative with verified CoAs looks like is described in our article Peptide Sciences Alternative.
Frequently asked questions
This article is for informational and research purposes only. All products are intended exclusively for in-vitro research and laboratory use, not for human consumption or ingestion.
Research context for English-speaking buyers
Most of our English-speaking customers ship to the UK, Ireland, Malta or other English-as-second-language EU territories. The regulatory picture differs per country.
- Relevant authorities
- MHRA (UK, post-Brexit), HPRA (Ireland, EU-aligned), FDA Section 503A bulks list (US, restricted Cat 2 status of several peptides as of 2026)
- Customs and VAT
- EU shipments include 19% VAT; UK shipments after Brexit are now extra-EU and may attract UK VAT plus a handling fee at import
- Typical shipping window
- EU 2-4 working days, UK 4-7 working days, other international 7-14 working days, depending on customs
Research-grade peptides shipped from our EU warehouse are sold for laboratory use only and are not authorised for human or veterinary therapeutic application in any of the destination jurisdictions. US customers should be aware that the FDA Section 503A bulks list classification (and the April 2026 reclassification of twelve compounds) only governs compounding pharmacies, not direct-to-researcher imports for non-clinical work. UK buyers should declare the consignment on import and may be asked for a research justification by HMRC. We provide a CoA per batch identified by colour code rather than serial number; customs sometimes asks for this document when clearing the parcel.