How to Read a Janoshik Certificate of Analysis

If you've spent any time researching peptide vendors, you've heard the name Janoshik Analytical. Janoshik is a Prague-based independent testing lab that has become the de facto gold standard for research peptide purity verification. When a researcher asks "is this vendor legit?", what they really mean is "have their products been independently tested at a real lab — and can I see the report?"

This guide walks through what a Janoshik Certificate of Analysis (COA) actually contains, how to read it, and how to spot the most common types of fake or misrepresented reports.

For research purposes only. Not for human consumption. This article is educational; it does not constitute advice about any specific batch or supplier.

Why Janoshik specifically?

There are dozens of analytical labs that can test peptides. Janoshik became the community reference for several reasons:

1. Independent. Janoshik is not owned by, affiliated with, or paid commissions by any peptide manufacturer or reseller. Their job is to test what's in the vial.
2. Transparent. Their test reports follow a consistent format. Once you've read one, you can read all of them.
3. Searchable database. Janoshik publishes verification tools that let you cross-check a report ID against their internal records, making it harder to fake.
4. Method consistency. They use HPLC (high-performance liquid chromatography) and mass spectrometry as their primary purity techniques, which are the right tools for peptide analysis.

When we say "Janoshik-verified" on this site, we mean the manufacturer's specific batch has been tested by Janoshik and has a real, verifiable report. Not "the manufacturer has tested some product some time."

Anatomy of a Janoshik COA

A real Janoshik COA contains the following fields. Here's what each one means and what to look for:

1. Report header

• Report number — A unique identifier you can cross-check against Janoshik's verification system. Always present, always alphanumeric, always specific to that test.
• Date of analysis — When the test was performed. This should be recent enough to be relevant (within the last 12 months for most peptides). An undated COA is a red flag.
• Customer/sender — The lab or company that submitted the sample for testing. This will be the manufacturer's name, not the reseller's.
• Sample identification — The product name as labeled on the vial that was tested.

2. Sample description

• Peptide name — The compound being tested (e.g., "BPC-157", "Retatrutide")
• Lot/batch number — The manufacturer's batch identifier. This is the most important field for verification. You should be able to match this against the batch number printed on your physical vial.
• Expected molecular weight — The theoretical molecular weight of the peptide
• Sample form — Usually "lyophilized powder"
• Sample mass tested — The amount of material Janoshik received

If the batch number on your vial does not match the batch number on the COA, the COA is not for your specific batch — it's a manufacturer reference document, which is different.

3. Test methods

A real Janoshik COA lists the analytical methods used. The standard set is:

• HPLC (High-Performance Liquid Chromatography) — measures purity by separating compounds based on chemical interactions with a column. Peptide purity is typically reported as a percentage of the total peak area.
• Mass spectrometry (MS) — confirms the identity of the peptide by measuring its molecular mass. The observed mass should match the theoretical mass within tight tolerance.
• Sometimes additional tests — water content, acetic acid content, related substances

Each method has its own results section. A COA without method documentation is incomplete.

4. The HPLC purity result

This is what most people look for first. You'll see a number, usually expressed as a percentage:

• ≥99% — High-purity research grade. This is what you want for any serious work.
• 97–99% — Acceptable for many research applications, less ideal for sensitive comparative studies.
• <97% — Should make you ask questions about what the impurities are and whether they affect your endpoints.

Below the headline number, a real COA will include:

• Chromatogram image — A graph showing the actual peak data. The main peptide peak should be tall and narrow; impurity peaks should be small. A flat line with no chromatogram is a major red flag.
• Retention time — The time at which the main peak elutes. This is a fingerprint that helps identify the compound.
• Peak area data — Numerical values backing up the percentage

5. The mass spectrometry result

The MS section confirms identity:

• Theoretical molecular mass — what the compound should weigh
• Observed molecular mass — what was measured
• Difference — should be within ~1 Da (Dalton) for peptides; larger differences indicate either degradation or a different compound entirely

A mismatch here means the vial does not contain what the label says — and that's a hard stop.

6. Lab signature and footer

• Lab signature/stamp — Janoshik's official mark
• Contact information — Janoshik's address and contact info
• QR code or report URL — Newer Janoshik reports often include a QR code that links back to their verification page

How to actually verify a COA

Here's a practical workflow:

1. Check the batch number on your vial against the COA. They must match exactly.
2. Check the date. Was the test recent enough?
3. Look at the chromatogram. Is there an actual graph with peaks, or just a typed percentage?
4. Check the HPLC purity number. Is it ≥99%? If not, why?
5. Check the mass spec result. Does the observed mass match the theoretical mass?
6. Check the report number. Cross-reference it against Janoshik's verification system if you have access.
7. Compare against the manufacturer's label. Do the molecular formula and MW on the COA match what's printed on the vial?

If anything looks off, ask questions. A legitimate vendor will engage with COA verification questions; a sketchy one will deflect or pretend not to understand.

Common red flags in fake or doctored COAs

1. The COA has no chromatogram image — just a typed purity percentage. Real labs always include the graph.

2. The batch number on the COA doesn't match the vial. The COA is for a different batch entirely. The vendor is showing you a "representative" report for a different product.

3. The COA is undated or the date is suspiciously old (>12 months).

4. The "lab" on the COA is one nobody recognizes and doesn't have a public web presence. Real analytical labs have websites and contact information.

5. The purity number is suspiciously round (always exactly 99.0%, for example) and never varies between batches. Real HPLC measurements vary slightly between runs.

6. The COA is the same across multiple products — same date, same numbers, same chromatogram, just a different product name. This is a copy-paste fake.

7. The vendor "can't find" the COA for the specific batch you bought, but assures you it's "the same as the previous batch."

8. The COA references a lab address that doesn't exist or matches a residential building. Look up the lab's address in a search engine.

How TrueStandard Labs handles COAs

We source exclusively from manufacturers whose products have been independently verified by Janoshik. When your order ships, the manufacturer's Janoshik COA for your specific batch is delivered to your inbox along with your tracking number — automatically, no requests needed.

The COA is the actual PDF the manufacturer received from Janoshik. We don't modify it, summarize it, or hide anything. If the COA shows 99.2% purity, that's what we tell you. If a future batch shows 98.7%, we tell you that too.

We're also building our own independent third-party batch verification program — launching in the coming months — to add an additional layer of quality assurance on top of the manufacturer-level reports.

Quick checklist for any COA you receive

• Batch number on COA matches vial label
• Test date is within the last 12 months
• Includes a chromatogram image, not just a typed percentage
• HPLC purity ≥99% (or you understand why it's lower)
• Mass spec confirms identity within tolerance
• Lab is real and findable online
• Report number can be cross-referenced if a verification system exists

If any of these fail, ask the vendor. If they can't answer, walk away.

---

This article is part of our trust and verification series. Learn more about our COA delivery process or browse our catalog of Janoshik-verified compounds.