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Quality & Testing

What Is Janoshik Testing? How Eternal Peptides Verifies Purity

A Certificate of Analysis is only as useful as your ability to interpret it — and only as credible as the laboratory that produced it. This page explains what Janoshik Analytical tests for, why we use an independent third-party rather than in-house QC, what each analytical method actually measures, and how to read a research peptide COA so you know what you're looking at when one arrives with your order.

Published: April 2026·~1,200 words·5 min read

Why Third-Party Testing, Not In-House QC

The problem with a supplier testing their own products is structural: they have a financial interest in the outcome. This doesn't require anyone to be dishonest — it's simply that the incentive structure of self-reported testing is misaligned with objective quality assessment. An independent laboratory has no stake in what your compound tests at. Their entire business model depends on producing accurate, reproducible results that clients trust — a poor reputation for testing integrity destroys that business.

Janoshik Analytical is an accredited third-party laboratory specialising in research compound analysis. They test peptides, SARMs, nootropics, and other research chemicals for suppliers and individual researchers. They have no commercial relationship with us that would compromise their results — they simply test what's sent to them and report what the instruments show.

The second advantage of Janoshik specifically is verifiability. Every COA they produce carries a unique report number. You can contact Janoshik directly, provide the report number, and verify the result against their records. That's not possible with in-house testing certificates, which have no independent verification mechanism.

The Five Tests — What Each Measures

1. HPLC Purity Analysis

High Performance Liquid Chromatography separates the components of a dissolved compound sample as they pass through a column under high pressure. Different components interact differently with the column's stationary phase and elute (exit) at different times, producing a chromatogram — a plot of detector signal over time with peaks corresponding to each detected component.

Purity is calculated as: area of target peptide peak ÷ total area of all peaks × 100. A result of ≥98% means at least 98% of the detectable material in the sample corresponds to the target compound. This is the minimum threshold for research-grade material — below 95% is not considered acceptable for most research protocols. The HPLC chromatogram itself, if included in the COA, will show the main peak and any secondary peaks representing impurities.

2. Mass Spectrometry Identity Confirmation

Mass spectrometry ionises molecules in the sample and measures their mass-to-charge ratio (m/z), producing a spectrum that functions as a molecular fingerprint. For research peptides, the COA will list the observed molecular weight (or m/z values for multiple charge states in larger peptides) alongside the theoretical molecular weight calculated from the compound's amino acid sequence.

A match within 0.1–0.2 Da confirms the compound is the peptide it claims to be. A significant discrepancy — off by the mass of an amino acid, or showing an unexpected modification — is a red flag. HPLC tells you how pure the compound is; mass spec tells you it's actually the right compound. Both are necessary for a complete quality picture.

3. Sterility Testing

Sterility testing checks for viable microbial contamination — bacteria and fungi. The sample is incubated in appropriate growth media under conditions that would support microbial growth, then assessed for turbidity or colony formation. A result of "no growth detected" over the test period (typically 14 days for aerobic and anaerobic organisms) confirms sterility. All batches supplied by Eternal Peptides Wholesale must pass sterility testing before release.

4. Endotoxin Testing (LAL Assay)

Bacterial endotoxins — lipopolysaccharides (LPS) from gram-negative bacterial cell walls — are not destroyed by autoclaving or other standard sterilisation methods. Even trace endotoxin contamination causes potent inflammatory responses and can invalidate in vitro and in vivo research results by producing biological effects independent of the compound being studied.

The LAL (Limulus Amebocyte Lysate) test detects endotoxins at picogram-per-millilitre sensitivity, expressing results in endotoxin units per milligram (EU/mg). Research peptides intended for injection-route use typically require <1 EU/mg. The COA will state the observed endotoxin level and whether it meets the specified limit.

5. Heavy Metals Analysis

Heavy metals testing (typically ICP-MS — Inductively Coupled Plasma Mass Spectrometry) screens for elemental contaminants including lead, arsenic, mercury, and cadmium. These can be present as trace residues from synthesis reagents, equipment, or raw materials. For research-grade peptides, heavy metals must be below defined limits, and Janoshik reports observed levels alongside regulatory limits on the COA.

Reading a Janoshik COA: What to Look For

Report Number
Use this to verify the COA directly with Janoshik. Cross-reference the batch number on your vial to confirm the COA matches your specific batch.
HPLC Purity %
Look for ≥98.0%. Below 95% is not acceptable for most research applications. The chromatogram (if included) should show a dominant single peak with minimal secondary peaks.
Mass Spec (Observed vs Theoretical MW)
Observed and theoretical molecular weights should match within 0.1–0.2 Da. Any larger discrepancy warrants investigation. "Conforms" on the COA indicates a confirmed match.
Sterility
"Sterile" or "No growth detected" is the passing result. Any indication of growth means the batch should not be used.
Endotoxin (EU/mg)
The observed EU/mg value should be below the stated limit. For injectable-route research applications, <1 EU/mg is the standard threshold.

COAs for all Eternal Peptides Wholesale products are published on individual product pages — available before you order, not only after. If you have a question about any COA, contact us directly and we will provide documentation support.

All Eternal Peptides products are Janoshik-verified
HPLC purity ≥98% · Mass spec identity · Sterility · Endotoxin · Heavy metals · COA on every batch, every product page
View Full Research Catalogue

Frequently Asked Questions

What is Janoshik testing?
Janoshik Analytical is an independent accredited laboratory providing analytical testing for research compounds including peptides. Testing includes HPLC purity, mass spectrometry identity, sterility, endotoxin (LAL), and heavy metals. COAs include a report number independently verifiable on the Janoshik website. It is the benchmark third-party testing standard in the research peptide market.
What does HPLC purity mean?
HPLC purity is the percentage of the measured sample that corresponds to the target compound — determined by the ratio of the target peak area to total peak area on the chromatogram. ≥98% is research grade. It tells you how pure the compound is but requires mass spectrometry to confirm identity.
Why does endotoxin contamination matter in research?
Endotoxins cause potent inflammatory responses at trace concentrations and are not removed by autoclaving. In animal or cell culture research, endotoxin contamination can produce inflammatory readouts that are attributed to the test compound when they're actually an artefact of contamination. Endotoxin testing using the LAL assay is the only way to rule this out. This is particularly critical for experiments where inflammatory pathway activation is a primary endpoint.
How do I verify a Janoshik COA?
Use the report number printed on the COA and contact Janoshik Analytical directly via janoshik.com to confirm the result against their laboratory records. This is the definitive verification step — no supplier-issued document can replicate this external verification.
Does Eternal Peptides test every batch?
Yes — every production batch, every compound, before release. We do not supply batches that have not passed Janoshik testing. COAs are published on each product page and can be downloaded before you order. If a batch fails any test parameter, it is not released to customers.
Important: Purity and identity verification data relates to research-grade compound quality standards only. It does not constitute or imply TGA registration, therapeutic efficacy, or safety for human use. All products supplied by Eternal Peptides Wholesale are for qualified laboratory research purposes only — not for human therapeutic use or consumption.