Janoshik test report: how to read one, and how to verify it

Janoshik Analytical is an independent analytical laboratory in the Czech Republic that accepts samples from anyone and returns a one-page report. It has no stake in any catalogue.

Over the last few years it became the address peptide suppliers send their lots to, for two plain reasons: it accepts small submissions, and it publishes each report at a stable address, so a buyer can check the document without going through the supplier.

That second point is the whole argument.

A certificate that exists only as a JPEG on a shop page proves nothing, because a JPEG can be edited in a minute.

A report that carries a number the laboratory itself will confirm is a different object: to forge it you would have to forge the laboratory.

Janoshik is not the only laboratory doing this work.

Freedom Diagnostics, Colmaric Analyticals and ILS run comparable programmes, and a large manufacturer will often hold an in-house certificate as well.

The reading method below applies to all of them; the field names move, the questions do not.

A report is short on purpose. Every line is a fact that can be checked, and a line that is missing is a fact nobody wanted to state.

The field-by-field reading of a full certificate, including the fields Janoshik does not carry, is in how to read a peptide COA.

Reverse-phase HPLC: how clean

The sample is dissolved, pushed through a column and detected by UV at 214 nm, the wavelength of the peptide bond.

Each compound leaves the column at its own time and draws a peak. Purity is the area of the main peak divided by the area of everything that appeared, expressed as a percentage.

What this settles: the sample is one compound rather than a mixture. What it does not settle: which compound.

A 99.4 % figure on a vial of the wrong peptide is a very clean vial of the wrong peptide. The arithmetic behind the percentage, and why 99 % is a weaker claim than it sounds, is in what 99 % purity actually means.

Identity: which molecule

The laboratory names the compound it found; in a blind test it is not told what to look for.

Where mass spectrometry is run, an option at some laboratories, the dissolved sample is ionized and its mass measured. That measured mass is compared with the mass computed from the declared sequence.

A GHK-Cu sample must answer near 340.4 for the free tripeptide; a TB-500 sample near 889.0; a 15-residue BPC-157 sample near 1,419.5.

A difference of one residue shows up immediately, and so does a sequence built in the wrong order only if the laboratory also runs a sequencing step, which a standard report does not.

What this settles: identity, to the nearest mass. What it does not settle: stereochemistry, or two sequences that happen to share a mass.

Net peptide content: how much you actually bought

A lyophilized peptide is an acetate salt and carries residual water. Net content, measured by amino-acid analysis or by nitrogen determination, states the share of the powder that is the peptide chain itself.

A report that gives purity and identity but not net content is still a real report. It simply leaves the most expensive question open.

Further reading: suppliers scored on their lab reports.

Four steps, and none of them require trusting the shop page the document was found on.

1. Read the test number at the top of the page, and type it into the laboratory own lookup rather than clicking a link on the shop page. A link can point anywhere; an address typed by hand cannot.
2. Compare what comes back with the page you were shown: the same compound, the same date, the same purity figure. A number that opens a different document, or nothing at all, ends the conversation.
3. Match the lot on the report against the lot the product page says is shipping, and enter the verification key with the task number. This is the step almost nobody does, and it is the one a re-used certificate cannot survive.
4. Look at the photograph. If the vial in the picture wears the supplier label, the document describes the finished product. A bare vial, or a label from another brand, describes something else.

Where a supplier publishes the report matters as much as whether it has one.

A certificate on the product page, dated, with a lot number, beats a promise to send one on request every time.

OXpeptides publishes its 4 Janoshik reports, for GHK-Cu and Retatrutide, in the COA library and on the product page, listed in the table further down.

Yes: Janoshik Analytical is a real, independent laboratory, and its reports can be checked on its own site with a task number and a key. That is the short answer to the question buyers type most often.

The longer one is about what "legit" covers.

The laboratory is a company registered in the Czech Republic that has tested peptides, steroids and other compounds for private clients for years.

It sells analyses, not products, so a high or a low purity figure earns it nothing.

Its main strength is the public lookup: each report gets a task number and a key, and the pair opens the original on the laboratory's servers.

Buyers on forums trust it for that reason, and suppliers who show a Janoshik page without a working number are quickly called out.

What "legit" does not mean:

• It is not an accreditation of the seller. Janoshik tests what it receives. It does not inspect a warehouse, a factory or a shop.
• It is not a GMP or pharmacopoeia release. A Janoshik report is the analysis of one sample, not a batch release under a quality system.
• It is not proof for a lot it does not name. A real report on lot A says nothing about lot B.

Used that way, a Janoshik report is one of the few pieces of evidence a buyer can check alone, in under a minute, without trusting the seller. That is all it promises, and it keeps that promise.

Every report OXpeptides has received is listed below, read from the catalogue. Click a task number to open the original on Janoshik's verification page, then compare the lot, the date and the purity with the product page.

"Measured" is the amount of peptide Janoshik found in the vial, to compare with the size on the label.

The full documents, with the photograph of the tested vial, are in the COA library. For retatrutide, the reports of the three sizes are also set out in the retatrutide buying guide.

Outright forgery is rare, because it is easy to catch. What circulates instead is real documents used dishonestly.

1. The manufacturer certificate. A genuine report on a bare vial, submitted by the factory, shown as though it described the reseller finished product. Recognised by the photograph: no label, or a label in another alphabet.
2. The frozen certificate. One report from 2023 still on the page years later, under four different lots. Recognised by the date, and by a lot number that never changes.
3. The cropped page. The purity figure kept, the test number and the sample name cropped away. Recognised by what is missing.
4. The good-lot submission. A supplier submits the cleanest vial of a run and sells the rest. Nothing on the page reveals this, which is why a certificate per lot, not per product, is the thing to ask for.
5. The average on a blend. A four-peptide vial reported as a single purity figure. A blend must carry one figure per component, one peak per component. The case of the KLOW blend shows what a correct blend report looks like.

A report is a statement about one sample on one day. Reading it as a statement about a company is where buyers get hurt.

• It says nothing about the next lot. Purity is a property of a production run, not of a brand. A supplier who published a fine report in March owes you a fresh one for the vial shipped in September.
• It says nothing about storage or shipping. A sealed lyophilized vial is stable, and a report issued before a summer in a warehouse describes the powder as it was, not as it is. The storage rules are in lyophilized peptides: storage and shelf life.
• It says nothing about sterility or endotoxin. Those are separate analyses, ordered separately, and a purity report does not include them.
• It says nothing about anything living. A purity figure is chemistry. Research use only. Not for human or veterinary use.

Further reading: GHK-Cu 100 mg, report #217016.

The OXpeptides reports come from Janoshik Analytical, one per size.

Each is published in the COA library and on the product page, with the purity figure and the date, never an estimate and never a figure borrowed from a previous run.

The catalogue names the laboratory only where a signed report exists, and the measured purity figure lives on the certificate.

The copper tripeptide is on the GHK-Cu page; the seven-point method for judging any supplier, certificate included, is in how to check a peptide supplier.

Further reading: GHK-Cu vs AHK-Cu.