Retatrutide and tirzepatide arrive as the same small heap of white powder. Nothing you can see tells you which one is in the vial. One line on a lab report decides whether anybody actually checked.
Two ways to ask the same laboratory
Confirm this is retatrutide
315
USD, and the laboratory is
told the answer first
Identify this powder
360
USD, and it has to
work the answer out
Janoshik Analytical public price list, September 2026
Look at the vial for as long as you like. It will not tell you a thing.
Clear glass, about the size of your thumb. A metal ring crimped tight around the neck. A small plastic cap. A label with one word and one number on it.
Turn it toward the light. At the bottom there is a little white powder. Sometimes a thin dry disc of it. Sometimes a scatter, like spilled sugar nobody wiped up.
That is everything the vial gives you. Looking tells you the glass is clean and the printer works.
Here is why that matters more than it sounds.
Semaglutide, tirzepatide and retatrutide are three different compounds. On one seller's catalogue today, semaglutide starts at $60, tirzepatide at $100 and retatrutide at $105. Same size vial, same white powder, forty-five dollars between the cheapest and the dearest.
Now open both product photos and find the difference in the powder.
You cannot. Nobody can. There is no shade to compare, no smell through a sealed cap, and nothing a person can weigh at these amounts on any scale they own.
So the one thing you are actually paying for, which is identity, is the one thing your own senses cannot check.
The label only tells you what somebody typed. The seal only tells you the vial was sealed. And if this is a first order, you have never seen a verified vial in your life, so every vial looks correct.
Somebody on r/Peptides said the quiet part out loud:
“So aside from paying a fortune to test them, how do i know if its good?”
r/Peptides
He is right on both counts. Telling those three apart takes an instrument. You do not have one, almost nobody does, and paying a lab yourself means paying after your money is already gone.
So the question changes shape. It stops being "can I check this myself." It becomes "can I trust a check that somebody else paid for."
Which leaves one piece of paper doing all of the work. A lab certificate. A logo, a batch number, a big figure next to the word purity.
Sometimes that paper proves a great deal. Sometimes it proves almost nothing. And the purity figure will not tell you which kind you are holding, because that is not where it gets decided.
It gets decided earlier, in one small box on the form that travels with the sample.
Every vial sent to a testing lab travels with a form. The box sits on it, about halfway down, and it is the part almost nobody thinks about.
Whatever gets written in that box is the question the lab will answer. And the answer that comes back is only ever as good as the question that went in.
Here is the question most sellers ask.
"Confirm this sample is retatrutide. Report purity."
The lab is told the answer before it starts. It goes and looks for retatrutide. It finds some, or it does not.
Read that again, because it is doing something quiet.
The lab has been handed the conclusion. Its job is now to agree or disagree with one thing. That is a yes or no question about a single compound, and a yes is worth exactly as much as the person who wrote the question.
Now here is a different question.
"Common GLP-1 peptide blind test (Semaglutide, Tirzepatide and Retatrutide)"
Nothing has been claimed. The lab is not told which one it is. It has to work that out and say so.
Same lab. Same machine. Roughly the same money. Completely different piece of paper at the end.
The first question can only ever confirm what the seller already believes. The second one can contradict him.
r/Peptides / quoted verbatim
This would be a detail if the compounds were easy to tell apart. They are not.
Semaglutide, tirzepatide and retatrutide arrived in that order. They are different molecules, and retatrutide is the newest of the three.
In a vial, all three are the same sight. A little freeze dried powder at the bottom of the glass, somewhere between white and off white. No colour difference worth the name. No smell. Nothing a person can weigh or judge at home.
So if a batch sold as the expensive one is actually the cheap one, nothing about the vial will tell you. Not the label. Not the seal. Not the box. Not the photo the seller posted in the group chat.
Only a machine can tell you. And what the machine reports depends on what it was asked.
“So aside from paying a fortune to test them, how do i know if its good?”
r/Peptides
That is the honest position most buyers are in. Sending your own sample to a lab costs real money and takes weeks. Almost nobody does it. So the certificate the seller publishes is, in practice, the only evidence there is.
Which is exactly why the question in that box is worth ten seconds of your attention.
Janoshik 163572 / 25 May 2026
Below is a real report. Not an example, not a template. It is a published Retatrutide 20mg certificate from Janoshik Analytical, an independent laboratory that a lot of this market uses, read next to one from a different laboratory that was asked a different question.
Most people skip to the purity figure. The line that earns it is higher up, in the box marked Tests requested.
Crystal Peptides, Retatrutide 20mg. That box reads, in the laboratory's
own wording, “Common GLP-1 peptide blind test (Semaglutide, Tirzepatide and
Retatrutide)”. The laboratory was handed a powder and told to say which of the
three it was. Batch RT6423CP, task #163572, analysed 25 May 2026
by Janoshik. Result 22.43 mg and 99.744%.
American Peptides, Retatrutide 20mg. No such box. Their certificate lists the methods run instead: identity by LC-MS/MS, purity by RP-HPLC, content by HPLC quantitation. Good testing, carefully reported, and not a blind test. The laboratory was told what it had.
That is the difference this page is about, and it is visible on the document in about ten seconds once you know which box to read.
Janoshik sells that test as its own item. Their description of it is plain: it will identify which peptide the sample is, and report how much of it is there and how pure it is. Identify, not confirm. That is the whole difference.
Now the part nobody selling this seems to say out loud.
More than one seller already buys this test. Of the certificate libraries we have opened, two carry a blind test ordered from the same laboratory, and both reports say so on the face of the document.
What is strange is that neither of them explains it. The line sits there on the certificate, in the language of a lab invoice, and it gets published as if it were the same as any other test. It is not, and a buyer deserves to know why.
So take this as a standard, not a sales point. If two sellers already meet it, a third one should be able to.
You can run this on anyone, including us, before you make an account or type an email address.
THC88ILYEN8S at janoshik.com/verify/, and American Peptides'
is COA7599 at bioviridians.com/coa-search.html. Both checks happen on the
laboratory's site, not the seller's.No report anywhere. A report with no lab named on it. "Tested to the highest standards" with nothing behind it. A purity number that only appears in the sales copy. A certificate with the batch number blanked out. A verify code that leads nowhere.
An outside lab named on the document. A batch number you can match to the product. A request line that asks the lab to identify the compound rather than agree with a label. A code you can check on the lab's own website. The lab's own photo of the vial.
“Is there a way to tell if their third party testing is real or if it has been faked?”
r/Peptides
Step six is the answer to that one. A PDF can be edited by anyone with a laptop. A result sitting on the lab's own server cannot.
Batches RT6423CP / RETA20-0803
If we only told you what it covers, we would be doing the thing this page is complaining about. So here is the other half.
RT6423CP and RETA20-0803 and nothing else. A certificate is a photograph of one moment,
not a promise about every future vial.“This incident is a textbook example of why the industry needs to transition from 'vendor-provided PDFs' to a more rigorous, third-party audit model.”
r/Peptides
We agree with that, including the part that is uncomfortable for us. A blind test is a step up from a vendor PDF. It is not the finish line.
While you have the report open, look at the results line above the purity figure.
One vial is labelled 20mg and the laboratory measured 22.43 mg. The other is labelled 20mg and measured 20.22 mg.
There is a rough standard people in this market use when they get their own testing done: a vial should hold at least 90 percent of what the label says. Under that, they call it short. A short vial is a common complaint in this market.
This batch came in at about 107 percent of label. Slightly over, not under, which is what a small deliberate overfill looks like when the fill is done carefully.
It is on the same page as the purity number everybody quotes. It has been there the whole time.
Run the six steps above on whoever you are considering. Then run them on us. The certificates are on the site, with the batch numbers and the verify codes on them.
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 checking steps as a one page sheet, in plain language, so you can run it on any seller in any country, including the ones this site links to.
You are on the list.
The six steps come by email, as one page you can print.
One certificate that ran a blind test, one that did not.
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.