Most people check two things on a peptide lab report: the purity number, and whether one exists. There are eleven parts, and at least six of them tell you something the purity number cannot. Here is a real one, explained.
Anatomy of a certificate
The fields to read, in the order they appear on the report
A lab report is not a quality badge. It is a record of one test, on one sample, on one day, paid for by one company.
Everything useful about it follows from that. It describes a specific event. Whether it is worth anything depends on whether that event has anything to do with the vial you are holding.
That link gets made, or broken, in the parts nobody reads.
Everything below walks one real, published document: the Janoshik test report for
Crystal Peptides Retatrutide 20mg, task #163572, batch RT6423CP,
analysed 25 May 2026. Results 22.43 mg and 99.744%, verification key
THC88ILYEN8S.
It is on their own site, free to open, and checkable at the laboratory rather than at the shop. Open it alongside this page.
Janoshik 163572 / 31 August 2026
The top of the page should carry the name of a lab, with contact details, that is not the shop selling you the vial. On this one it is Janoshik, with their own email and website.
Fails when: the seller's own logo is at the top, or no lab is named anywhere. That is an internal note. It might be honest. It is still not proof, because the people with money riding on the answer wrote it.
Here it is #163572. It is how the lab files the job on their side. That
matters because it means the record exists somewhere other than your PDF.
Fails when: missing, or the same number shows up on reports for different products. One job number on three compounds means at most one of them is real.
Most people see "a date" and move on. There are three. Ordered 24 August. Sample arrived 28 August. Tested 31 August 2026.
Three dates in order show a clean chain with no gaps. Four days in the post, three days to test. A report showing the test happening before the sample arrived is describing something impossible, and that does happen.
Fails when: there is one undated line, or the date is so old the batch cannot still be in stock. A purity number with no date is a wish, not a measurement.
Two separate boxes, on purpose. "Client" is who paid for the test. "Manufacturer" is who made the powder. Here the client reads Crystal Peptides EU and the manufacturer reads their own domain, so the seller paid an outside lab to check its own product.
If those two names are different, the report is telling you there is a middleman. That is not automatically bad. Most of this trade has one. You should just know rather than guess.
Now the important part, and almost nobody says this out loud. The manufacturer box is filled in by whoever sent the sample. The lab does not go and check. They test the powder in front of them and write down what the customer told them about where it came from.
So this box is a claim, not evidence. On this report it reads the seller’s own name, because that is what the seller told them. It records who commissioned the test. It tells you nothing about which building the powder was made in, and the same is true of anyone else’s.
Which means a seller advertising that they manufacture in Europe cannot prove it with a lab report. If where it was made matters to you, ask directly and see whether the answer comes with anything checkable attached.
Fails when: a shop sends you a report with its name in neither box. They have handed you somebody else's paperwork about somebody else's batch. Also treat "manufactured in Europe" as unproven unless it comes with something other than a certificate, because the certificate cannot carry that claim.
Here, RT6423CP. This is the most important thing on the page, and the
reason the rest of it means anything.
A report with no batch number describes an anonymous sample. It could be a genuine test of a completely different production run and you would never know. The batch code has to be on the report and on the vial that turns up, and they have to match.
Fails when: the box is blank, or vague like "Retatrutide 10mg", or the code is on the report but nowhere on the vial. One old report covering a whole product line for two years is the usual version of this.
Almost nobody reads this box. It is the most revealing one on the page.
Here it says: "Common GLP-1 peptide blind test (Semaglutide, Tirzepatide and Retatrutide)".
That word blind is doing a lot of work.
In a normal test, the lab is told what the sample is meant to be and checks whether that fits. In a blind test, the lab gets a sample that could be any of three similar drugs and has to work out which one it is. Janoshik's own description says the test will identify the peptide, and measure how much is in the vial and how pure it is.
The difference is real. A normal test can only confirm somebody's claim. A blind test says what the powder is without the lab being pointed at an answer first. And the cheap swap in this corner of the market is a different, older, much cheaper GLP-1 drug. Which is exactly what a blind test is built to catch.
Fails when: the box is missing, or names a test that does not do what the seller implies. Identifying, measuring purity and measuring amount are three different jobs.
The results box has Retatrutide 22.43 mg and Purity 99.744%.
These measure different things, and a vial can pass one and fail the other.
Purity is a proportion. It says how much of what is in there is the right compound. It says nothing about how much is in there.
Amount is the actual quantity. How many milligrams are in the vial against what the label says. A vial can be 99 percent pure and hold 7mg against a 10mg label, and the purity number stays beautiful the whole time.
On one group buy, the buyers wrote their own pass mark before ordering: at least 99 percent pure and at least 90 percent of the stated amount. Two numbers, because there are two questions.
This one has 22.43 mg against a 20mg label. Twelve percent over. Over is the right direction for an error to go, though twelve percent is a wide miss in either direction.
Fails when: only purity is given. Also watch for round numbers. Nobody rounds their way to three decimal places, and "over 99 percent" is a phrase chosen because it cannot be proved wrong.
Blank here. This is where a lab writes down anything odd: a degraded sample, a strange reading, a vial that arrived damaged.
Fails when: the box has been taken out of the template altogether. A form with nowhere to record a problem was built not to record one.
At the bottom: check this test at janoshik.com/verify/ with the code
THC88ILYEN8S.
This closes the last hole. Everything above could, in theory, be typed into a document by someone with an afternoon and a reason. A check code cannot, because the checking does not happen on the seller's website or on the PDF. You take the code to the lab and the lab tells you whether they wrote that report.
It is the only step in the whole process where you have to trust nobody in the supply chain. It takes about thirty seconds.
Fails when: there is no code, the code returns nothing, or you are told checking is "available on request", which moves the check back to an email the seller controls.
Below the report is a photo of the vial with the lab's own watermark on it. The sample box points at it.
That ties the paperwork to a real object photographed by an outsider when it arrived, rather than to a description typed by the seller. It also lets you compare that label against the one on what you receive.
Bioviridian Inc / lot RETA20-0803
Everything above is one laboratory's layout. Learn the layout and you can read one laboratory. Learn what each part is for and you can read any of them.
So here is the same compound, at the same vial size, from a different seller and a
different laboratory: American Peptides Retatrutide 20mg, lot
RETA20-0803, certified by Bioviridian Inc. The document looks
nothing like the one above. Every part is still there, and two are better.
The job number became a verification code. Janoshik prints a task number and a separate key. Bioviridian prints one code, COA7599, which is both. Same job, one field instead of two.
Three dates became two. Sample received 11 August 2026, certificate issued 17 August. The posting gap is still visible, which is the part that matters.
Client and manufacturer became one line. It reads Vendor: American Peptides. Less information than two boxes, and worth noticing.
Tests requested disappeared. In its place is an Analytical Methods list: identity by LC-MS/MS, purity by RP-HPLC at 214 nm, content by HPLC quantitation. That tells you what was run. It does not tell you the laboratory was working blind, and on this report it was not.
Two numbers became five. Identity, content 20.22 mg, purity 99.79%, endotoxin <0.05 EU/mL and heavy metals <0.01 ppm, each with its method and a conforms or fails column beside it. That is genuinely more than the first report carries.
The photo gained a chromatogram. Alongside the vial picture there is the actual HPLC trace with its retention time, and the mass spectrum underneath. You are being shown the measurement, not just its result.
Read those two documents side by side and the lesson is not which laboratory is better. It is that the parts are the same everywhere and the layout never is. Ask what each field proves, not where it usually sits.
This kind of report covers identity, purity and amount. It says nothing about contamination, and that gap is not a technicality.
The machines used here measure the molecule. They were never built to spot what is sitting around it. Independent write-ups of Janoshik's testing say it plainly: it confirms what the peptide is and how pure it is. Contamination is a different panel with a different report.
| Not covered | What it would catch |
|---|---|
| Bacterial residue | Bits left behind by bacteria. They survive heat and cause trouble on their own. A purity number cannot see them. |
| Sterility | Live bacteria, mould or yeast. You have to grow a culture to find out, not read a graph. |
| Heavy metals | Left over from making and cleaning the compound. |
| Leftover solvents | Chemicals from the process still sitting in the powder. |
A purity report covers identity, purity and amount. The four rows above come from a different panel with its own report, so ask for that one by name if it matters to you.
We put that here rather than letting you find it later. A guide to reading lab reports that hid the limits of its own author's lab report would be a bad guide before it was a bad advert.
Steps one and six. A lab that is not the seller, and a code you can check with that lab yourself.
A supplier who passes both has given you evidence. One who fails either has given you a PDF.
The report used throughout this piece is on the product page, with the lab named, the batch printed and the check code intact.
Every seller looks the same on the good day. Four things decide what happens on the bad one, and all four are published before you order if you go and read them.
Read the seller's own published pages, not their marketing, and none of these terms were written by us.
We will send the fields to read on any certificate as a one page sheet, in the order they appear on the report, with what each one means when it is missing.
You are on the list.
The field guide comes by email, as one page you can print.
One report, eleven parts, every field named.
It follows once our list is live, and nothing else is sent. We do not sell peptides and we are not going to email you about any.
One email with the sheet. Unsubscribe in one click. We do not share addresses.
Before you go
One sheet, in plain language, that you can run on any seller in any country. One column filled in from a published certificate, and one left empty for the seller you already have open.
You are on the list.
The sheet comes by email, as one page you can print.
Nothing else follows it. We do not sell peptides and we are not going to email you about any.
One email with the sheet. Unsubscribe in one click. We do not share addresses.