What does HPLC purity mean on a Janoshik COA?

HPLC purity represents the percentage of the target peptide relative to all detected impurities in the chromatogram. For single peptides, Janoshik reports this as a percentage (e.g., 99.022%). For blends containing multiple peptides, purity percentages are not reported because the method cannot distinguish between the intended compounds. A result above 98% is generally considered acceptable for research-grade peptides.

What's the difference between quantitative and purity testing?

Quantitative testing measures the total mass of peptide in the vial (e.g., 10.11 mg). Purity testing measures what percentage of that mass is the target compound versus impurities. A vial can contain the correct mass but low purity if synthesis byproducts are present. Both measurements are important — mass tells you how much material you have, purity tells you how clean it is.

Can a Janoshik COA be faked or altered?

Any PDF can be edited. Janoshik's defense against this is the verification key system — every legitimate report includes a unique alphanumeric key at the bottom that can be checked on janoshik.com/verify. If a vendor provides a Janoshik-branded COA but the verification key does not return matching data, the document has been altered or fabricated. Always verify before trusting the report.

What should I look for first when evaluating a Janoshik COA?

Check four things in order: (1) Does the verification key work on janoshik.com/verify? (2) Does the sample name match what you ordered? (3) Is the test date recent enough to correspond to your batch? (4) For single peptides, is the purity ≥98%? If any of these fail, request clarification from the vendor before proceeding.

How to Read a Janoshik COA: A Section-by-Section Breakdown

Q: What is a Janoshik Task Number and how do I verify it?

A Janoshik Task Number is a unique identifier assigned to each testing submission (e.g., #79605). At the bottom of every Janoshik report, you'll find a verification key (an alphanumeric string like L1SUYDCMGJU5). Enter this key at janoshik.com/verify to confirm the report is authentic. If the key doesn't verify, the document may not be genuine.

Q: Does every Janoshik COA include mass spectrometry and endotoxin testing?

No. Standard Janoshik testing includes quantitative mass measurement and, for single peptides, HPLC purity. Mass spectrometry (for molecular identity confirmation) and LAL endotoxin testing are add-on services that must be specifically requested and paid for by the vendor. If these sections are absent from a COA, the tests were not ordered.

Janoshik Analytical is the most widely recognized independent testing laboratory in the research peptide community. When a vendor publishes a Janoshik COA, they're providing third-party verification that didn't come from their own facility or their manufacturer's QC lab.

But a COA is only useful if you can read it. Most buyers glance at the purity number, see something above 98%, and move on. The report contains significantly more information than that — and understanding each section tells you not just whether the product is pure, but whether the data is verifiable, whether the test matches your batch, and what the vendor actually paid to measure.

This guide walks through a Janoshik peptide COA from top to bottom, explains what each field means, and shows you how to verify the report independently.

                Research Use Only: All analytical methods and compounds discussed in this article pertain to preclinical research materials. This content is educational and does not constitute medical advice.
            

Understanding Janoshik Report Structure

Janoshik COAs follow a standardized format. The first page contains the identification header, the results table, and the verification key. Additional pages (when ordered) may include chromatograms, mass spectra, and endotoxin data.

Every Janoshik report starts with the same core information. Here's what appears at the top:

Janoshik Report Header

Task Number Unique identifier (e.g., #79605)

Testing ordered Date the vendor requested testing

Sample received Date Janoshik received the physical sample

Client Name of the vendor or individual who submitted the sample

Sample Compound name as provided by the submitter

Manufacturer Source facility (often a contact email)

Batch Manufacturer's lot number (e.g., cetz00088678)

What to check in the header:

Task Number is present — This is your verification key. Without it, the report cannot be authenticated.
Sample name matches what you ordered — If you purchased BPC-157 5mg and the COA says "BPC-157 10mg," it may not correspond to your product.
Test date is recent — A COA from 12+ months ago may not reflect the current batch. Peptides degrade over time, and a fresh test is more relevant than an archived one.
Client name matches the vendor — If the vendor claims they submitted the sample, their name should appear here. If it shows a different client, the vendor may be republishing someone else's test.
Batch number is provided — This ties the report to a specific production lot. Without it, the COA could apply to any batch of that compound.

The Results Section: What Janoshik Measures by Default

Below the header, the report shows a results table. This is where the actual analytical data appears.

Janoshik's standard testing includes quantitative mass measurement for all submissions. This tells you how much peptide material (in milligrams) is in the vial.

For single peptides, the results table also includes a purity percentage. This is derived from HPLC analysis and represents the proportion of the target compound relative to detected impurities [1].

For peptide blends (e.g., CJC-1295 + Ipamorelin in the same vial), purity percentages are not reported. The method cannot distinguish between two intentional compounds, so only the mass of each component is measured.

Example Results Table:

Single Peptide (Tesamorelin)

Tesamorelin 10.11 mg

Purity 99.022%

Peptide Blend (CJC-1295 + Ipamorelin)

CJC-1295 (mod GRF 1-29) 5.07 mg

Ipamorelin 5.47 mg

Notice the blend shows no purity percentage — only mass per component. This is expected and correct for multi-compound products.

What the purity number means:

When reported, HPLC purity represents the area of the main chromatographic peak divided by the total area of all detected peaks. A purity of 99.022% means 99.022% of the UV-absorbing material in the sample is the target peptide, with 0.978% attributed to synthesis-related impurities such as deletion sequences, truncations, or side products.

What purity tells you: The compound is chemically pure relative to detectable synthesis byproducts.

What purity doesn't tell you: Whether the compound is actually the correct molecule, what percentage of the vial weight is active peptide versus counterion salt, or whether the sample contains endotoxins. For a full breakdown of these gaps, see What Your COA Isn't Telling You.

What's Not Included by Default

Janoshik's base service covers quantitative mass and, for single peptides, HPLC purity. Two other critical tests are available as paid add-ons:

Mass Spectrometry (MS) — Confirms molecular identity by measuring the mass-to-charge ratio of the compound. This verifies that the peptide is actually the molecule you ordered, not a structurally similar impurity with the same retention time [2].
LAL Endotoxin Testing — Quantifies bacterial endotoxin contamination in EU/mL using the Limulus Amebocyte Lysate assay [3]. This is essential for research involving immune pathways or cell viability, where endotoxin can confound results. (For a full breakdown of LAL methodology and why it matters, see our Endotoxin Testing Deep Dive.)

If your COA includes additional pages with chromatograms, mass spectra, or endotoxin results, the vendor paid for those tests. If those sections are absent, the tests were not ordered.

Critical distinction: The absence of MS or endotoxin data on a COA does not mean the product passed or failed those tests. It means the tests were not performed. A COA can only report what was measured.

The Verification Key: How to Confirm a Report Is Real

At the bottom of every Janoshik COA, below the signature line, you'll find two verification elements:

A QR code that links directly to the verification portal
An alphanumeric verification key (e.g., MI47PQERQEGG or L1SUYDCMGJU5)

This key is the only defense against COA forgery. A PDF can be edited in minutes. A Janoshik-branded header can be pasted onto any document. The verification key creates a link between the physical PDF and Janoshik's internal records that cannot be forged without compromising Janoshik's own systems.

How to verify a Janoshik COA:

Locate the verification key at the bottom of the report (below "Verify this test at www.janoshik.com/verify/ with the following unique key").
Go to janoshik.com/verify or scan the QR code.
Enter the alphanumeric key into the verification form.
Compare the returned information against the PDF the vendor provided — Task Number, compound name, test date, and results should match.

If the key doesn't return a result, or the returned data doesn't match the PDF, the document has been altered, fabricated, or recycled from a different submission.

Without Verification, a COA Is Just a PDF

Anyone with basic software can edit text, change purity numbers, swap compound names, or paste a Janoshik logo onto a manufacturer's in-house report. The verification key is your only proof the data is real. If a vendor's COA does not verify, you know nothing about the product's actual quality.

Quick Judgment Guide: Is This COA Trustworthy?

When evaluating a vendor's Janoshik COA, run through this checklist in order:

COA Quick Check

✅ Verification key works Enter key at janoshik.com/verify — data must match PDF

✅ Sample name matches COA compound = what you ordered

✅ Test date recent Within 6-12 months for current batch

✅ Purity ≥98% For single peptides (blends show mass only)

⚠️ No MS data Identity not confirmed — purity alone insufficient

🚫 No verification key Cannot authenticate — treat as unverifiable claim

Interpreting the checklist:

If the verification key fails — stop. The document is not trustworthy. Request a verifiable COA from the vendor.
If purity is <95% — the peptide may be under-purified, degraded, or synthesized with significant byproducts. Request clarification before use.
If no MS data — purity is confirmed, but identity is not. For critical applications, request MS confirmation or choose a vendor who includes it by default.
If the test date is old — peptides degrade over time. A 2-year-old COA may not reflect the current product. Ask whether the batch matches the report date.

Red Flags: When to Question a Janoshik COA

Not every issue is disqualifying, but certain patterns warrant additional scrutiny:

COA Warning Signs

No Task Number Cannot verify → not a legitimate Janoshik report

Client ≠ Vendor Vendor may be republishing someone else's test

Same COA, Multiple Batches Not batch-specific → one test used for all inventory

Test Date >12 Months Old May not reflect current product quality

No Batch Number Cannot tie report to specific lot → unverifiable traceability

None of these individually prove fraud. A vendor may legitimately use one COA for a single large batch. An older test doesn't guarantee degradation. But multiple red flags on the same report should prompt additional questions before you proceed.

What a Complete Janoshik COA Looks Like

A vendor committed to quality testing will provide a Janoshik report with:

Quantitative mass measurement — how much peptide material is in the vial
HPLC purity percentage — chemical purity relative to synthesis impurities (for single peptides)
Mass spectrometry confirmation — molecular identity verified (add-on, but critical)
LAL endotoxin result — biological contamination quantified in EU/mL (add-on)
Verifiable Task Number and key — proof the data is real

Together, these tests address four distinct categories of risk:

Quantity — Is there enough material in the vial?
Purity — Is the material free of synthesis impurities?
Identity — Is it the correct molecule?
Safety — Is it free of endotoxin contamination?

The verification step adds a fifth dimension: authenticity. It confirms the data is real, unaltered, and traceable to Janoshik's laboratory records.

Putting It All Together

Reading a Janoshik COA is not about memorizing chromatogram peaks or mass spectrometry charge states. It's about knowing what to check, in what order, and what each field actually means.

When a vendor hands you a COA, ask four questions in sequence:

Does the verification key work? — If no, the document is not trustworthy.
Does the sample name and batch match what I ordered? — If no, the COA may correspond to a different product.
Is the purity ≥98% (for single peptides)? — If no, the peptide may be under-purified or degraded.
Does the report include MS and endotoxin data? — If no, identity and biological safety were not confirmed. Decide whether that matters for your application.

The answers won't always be perfect. Not every vendor tests every batch. Not every COA includes MS or endotoxin. But knowing what to look for — and what's missing — puts you in a fundamentally stronger position than accepting a purity number at face value.

Frequently Asked Questions

What is a Janoshik Task Number and how do I verify it?

The Task Number is a unique identifier at the top of every Janoshik report (e.g., #79605). The verification key is an alphanumeric string at the bottom (e.g., L1SUYDCMGJU5). Enter this key at janoshik.com/verify to confirm the report is authentic. If the key doesn't return matching data, the document may not be genuine.

What's a good HPLC purity for research peptides?

For research-grade synthetic peptides, purity above 95% is generally acceptable, with most reputable vendors targeting 98% or higher. Purity below 95% may indicate incomplete synthesis, inadequate purification, or degradation. Always evaluate purity alongside identity confirmation (mass spectrometry) — a high purity number only matters if the compound is the right molecule.

Does every Janoshik COA include mass spectrometry and endotoxin testing?

No. Standard Janoshik testing covers quantitative mass and HPLC purity (for single peptides). Mass spectrometry and LAL endotoxin testing are add-ons that vendors must specifically request and pay for. If those sections are absent, the tests were not ordered — not that the product passed or failed.

Why don't peptide blends show a purity percentage?

HPLC purity measures the target compound relative to impurities. In a blend containing two intentional peptides (e.g., CJC-1295 + Ipamorelin), the method cannot distinguish between the two target compounds — both appear as "correct" peaks in the chromatogram. Janoshik reports the mass of each component instead of an overall purity percentage.

Can I verify a COA if I'm not the one who submitted the sample?

Yes. Janoshik's verification portal is public — anyone with the verification key can check whether a report is authentic. This is by design: it allows end customers to independently verify vendor claims without relying on the vendor's word.

Should I be concerned if a vendor reuses the same COA for multiple orders?

It depends. If the vendor is selling from one batch and the COA corresponds to that batch, reuse is legitimate. The concern arises when a vendor uses the same COA across batches synthesized at different times — the report no longer reflects the specific product you received. Ask whether the COA matches your batch, and verify the Task Number.

References

Zhou NE, Mant CT, Hodges RS. Comparison of silica-based cyanopropyl and octyl reversed-phase packings for the separation of peptides and proteins. J Chromatogr. 1991;548(1-2):179-193. PMID: 1658020
Sharma N, Kukreja D, Giri T, Kumar S, Shah RP. Synthetic pharmaceutical peptides characterization by chromatography principles and method development. J Sep Sci. 2022;45(13):2200-2216. PMID: 35460196
Levin J, Bang FB. Clottable protein in Limulus; its localization and kinetics of its coagulation by endotoxin. Thromb Diath Haemorrh. 1968;19(1):186-197. PMID: 5690028

Mass. Purity. Identity. Endotoxin. Every Batch.

Every Vantix Bio product ships with a Janoshik COA covering quantitative mass, HPLC purity, LC-MS identity confirmation, and LAL endotoxin testing — verified via Task Number.

View Catalog → More Research →

                Disclaimer: This article is for educational and informational purposes only. All products discussed are intended exclusively for in vitro laboratory research. They are not approved for human consumption, therapeutic use, or clinical application. Vantix Bio makes no claims regarding the safety or efficacy of any compound for any purpose other than qualified preclinical research.
            