Independent Peptide Testing Explained: Janoshik, Finnrick, and What a Third-Party Test Can and Cannot Tell You

Janoshik is a commercial analytical laboratory in Prague that tests samples sent to it by vendors and buyers, and Finnrick is a US company that gathers samples, sends them to partner laboratories and publishes ratings built from the results. Both can tell you what was in one sample on the day it was tested. Neither, on its own, can tell you what is in the vial you are holding.

Those two names come up in almost every conversation about research peptide quality, often as if they were interchangeable. They are different kinds of thing, and the difference determines what their results can carry.

A laboratory and an aggregator

Janoshik is a laboratory. A client sends a sample, pays for a set of analyses, and receives a report. It is the most cited testing name in the research-peptide market: vendors post its reports to support their listings, and buyers commission their own tests to check what they received. A June 2026 Chainalysis analysis of cryptocurrency flows in the gray-market peptide trade described it as widely regarded as the reference standard for purity testing in that market.

Each report carries an identifier tied to the lab's own record, and the lab runs an online lookup where that record can be retrieved. That is the feature that makes a Janoshik report checkable: the copy on a vendor's site can be compared with the copy on the lab's servers. Accreditation claims about the lab conflict across secondary sources, and we could not confirm them with the lab directly. If accreditation matters to you, ask for the certificate number and check it with the body that issued it.

Finnrick is not a laboratory. It is a for-profit company based in Austin, Texas that sources samples, anonymizes them, sends them to a roster of third-party labs and publishes the results. Samples come from public submissions and from Finnrick's own purchases. Its site lists roughly a dozen partner labs, mostly in the US, with Janoshik among them. HPLC is its primary requested method, and it reports identity, purity and fill (how much material is in the container against the label claim).

Finnrick turns those results into a rating for each vendor and product pair: the share of tests that pass a published standard, weighted toward recent tests, with thin histories pulled toward the average for that peptide. Its default public standard requires HPLC purity of at least 99.5 percent and fill within 35 percent of the label claim in either direction, with stricter standards available to paying members. It reported more than 11,000 published tests as of late September 2026. It says it sells no peptides and that no payment changes a rating; its revenue comes from memberships and testing services, including services offered to distributors. Corrections are published as records rather than silent edits.

What the numbers on a report mean

HPLC purity is a relative figure. A liquid chromatograph separates a sample into components, a detector measures what comes off the column, and the main peak is reported as a percentage of everything the detector saw. It is blind to anything the detector does not respond to, and it does not say what the main peak is. Our explainer on what an HPLC trace shows covers this in detail.

Mass spectrometry identity answers the question HPLC cannot: does the main component have the molecular mass of the intended sequence. A high purity result with no identity result tells you a sample is mostly one thing, not which thing.

Fill or quantity measures how much material is present against what the label states. A vial can be pure and still short.

Endotoxin, sterility and heavy metals are separate tests, ordered separately. A certificate that reports purity and identity has said nothing about any of them. The Chainalysis report flagged exactly this gap: vendors often post passing purity certificates that did not include sterility testing at all.

What a third-party test cannot tell you

Where the sample came from. A test describes the sample the lab received. If a vendor chose which vial to send, the result describes the vendor's best vial. Finnrick's practice of buying samples anonymously narrows this problem for its own purchases. It does not remove it for submitted samples, which is why it cross-checks submissions against samples it obtains itself.

Anything beyond one lot. A result covers one batch on one date. It says nothing about the next production run, or about how the material held up in storage and shipping. A vendor with one excellent certificate and a dozen untested lots has one data point.

Who paid, and why. Vendors pay for many of the tests published in this market, and choose which results to publish. That does not make the results false. It does make the set of published results a selection rather than a census.

Whether a threshold is strict. A pass is defined by whoever sets the standard. A fill tolerance of 35 percent either way is generous by pharmaceutical norms, and Finnrick publishes stricter standards for that reason. Read which standard a rating used before reading the rating.

Whether the document is real. A screenshot of a report is not a report. The protection a lab's verification system offers only works if someone checks the lab's own record and confirms that compound, result, date and batch all match. Our guide to reading a certificate of analysis lists the other ways certificates get faked.

How to use these services well

Treat a lab report as evidence about a lot, and a rating as evidence about a track record. The strongest position is both: a recent, verifiable report for the batch number on your vial, from a seller whose independently sourced results have held up over time. The weakest is a single impressive document with no batch number, no lab you can contact, and nothing to check it against.

Neither service is a regulator, and neither claims to be. Their results say nothing about whether a compound is safe or effective in a person. That is a question for clinical trials, and for most research peptides those trials have not been run.

Frequently asked questions

Is Janoshik legit?

It is a working analytical laboratory used heavily by vendors and buyers in this market, and its reports can be checked against the lab's own records. What a report proves is limited to the sample it describes: who sent it, which lot it came from and which tests were ordered all shape what it means.

Is Finnrick independent?

Finnrick states that it sells no peptides, endorses no vendors and accepts no payment to change ratings, and it publishes its methodology and corrections. It is also a for-profit company whose revenue includes testing services sold to distributors. Readers can weigh both facts.

Does a good Finnrick rating mean a vendor is safe?

No. A rating summarizes how a vendor's tested samples performed against a purity and fill standard. It does not measure sterility in most cases, does not cover untested lots, and says nothing about effects in people.

How do I verify a Janoshik report?

Use the lab's own verification lookup rather than the vendor's copy, and confirm that the compound, result, test date and batch identifier all match the report you were shown and the vial you received.

Sources:

The Assay is published by Merit Sciences, which sells research compounds and publishes its own certificates of analysis. Research use only.

For research use only · Not for human or veterinary use · No research compound discussed here is FDA-approved for any indication