Is Janoshik legit? What 337 public lab reports show

Short answer: yes, as a lab. Janoshik Analytical is an independent lab in the Czech Republic that performs HPLC purity quantification and mass-spec identity confirmation on research-peptide samples. Every test resolves to a verifiable record at verify.janoshik.com, and the QR codes on Janoshik certificates point to records on Janoshik servers, not on the vendor's site. The public listing shows failures next to passes. "Legit" does not mean a vendor's vial matches the report it links. That is a separate check, covered below.

For the lab itself - what it is, where it is based, and the current numbers from its public listing - see our Janoshik testing hub.

The longer answer below explains what we mean by "legit," how we checked the claim, and what the public data actually supports.

What we audited

We read Janoshik's public-tests listing into a structured corpus and extracted the headline fields from every readable report image — compound, purity percentage, identity confirmation, test date, batch ID, vendor. Our methodology page documents how the audit corpus is built; the Janoshik COA verification guide documents how a buyer can verify any individual certificate against the same public source.

For this audit we asked four narrow questions:

1. Are the certificates internally consistent — do compound, purity, and date fields agree across the report image, the listing metadata, and the verify URL?
2. Are the certificates externally verifiable — can a QR code on a vendor-published COA be cross-checked against the public database?
3. Is the methodology consistent — do tests in the same category use the same reported assays?
4. Are the failure cases visible — does the public database show identity-mismatch and pass/fail flags, or are negative results hidden?

What the data shows

Internal consistency

In our first pass over 200 reports in May 2026, listing-level metadata (sample, submitter, manufacturer) matched the report image content in every case where both were present. In the 30 June 2026 snapshot of 337 readable reports, five carry an identity-confirmation result of false. The public listing surfaces these alongside the passing ones rather than hiding them, which is what an honest lab does. The methodology language on each report is consistent within test category (HPLC purity reports use one template, mass-spec identity reports use another).

External verifiability

The QR codes on Janoshik-issued certificates resolve to specific URLs under verify.janoshik.com. Those URLs are not under vendor control, which is the structural reason a fabricated or edited PDF cannot pass QR verification — the QR resolves to a record at Janoshik's servers and that record either matches the printed certificate or it does not. Our five-step guide to verify a Janoshik report uses that property to catch counterfeits.

Methodology consistency

The 337 readable reports span about fifty Janoshik service names. Most fall into a handful of groups:

• Assessment of a peptide vial or vials - 171 reports, the largest group
• Common GLP-1 peptide blind test (the catchall for retatrutide / tirzepatide / semaglutide identity + purity) - 45 reports across its variants
• Anabolic-steroid analyses and blind screenings - 42 reports
• Compound-specific peptide analyses such as GHK-Cu, MOTS-c, BPC-157 and ipamorelin
• rHGH vial and growth-hormone assessments
• Single-assay services such as LCMS screening, endotoxin, sterility and pH

Within each category, the assays reported are consistent across vendors. A retatrutide blind test always returns identity confirmation plus a purity figure; a vial assessment always returns purity, identity, and sterility figures. There is no evidence of vendor-specific methodology shortcuts in the public corpus.

Failure visibility

This is the most important question. A "legit" testing lab is one that publishes failures alongside passes. The 337 readable reports in the 30 June 2026 snapshot contain:

• 304 reports where the labelled molecule was confirmed
• 5 reports where identity confirmation was flagged
• 2 reports with an explicit fail marker (a Follistatin 344 sample and a Sermorelin sample)
• 28 reports with no identity field we could read

The fact that failures appear in the public listing — the same listing vendors point buyers to as evidence of clean batches — is the behavioral signal that distinguishes Janoshik from a vendor-owned testing operation. Janoshik publishes the bad results, not just the good ones. For the two most-tested compounds, retatrutide and tirzepatide, we published a report-by-report breakdown of 116 public results in Janoshik tirzepatide and retatrutide results.

What "legit" doesn't mean

Three caveats that buyers reading Janoshik certificates should hold in mind.

The public database is self-selected. Janoshik tests what is sent to them. Vendors choose which batches to submit publicly. A vendor that fails internal pre-tests can decline to submit those batches — which means the public corpus is biased toward passes. We quantified this bias: median purity across our 337-report snapshot is 99.7%, which is the self-selection effect, not a refutation of the industry-level 43% failure figure that includes private and withdrawn submissions.

A QR-verified COA does not certify the vial in your hand. The COA certifies a specific batch. Vendors can publish a real Janoshik certificate from a tested batch and ship vials from a different, untested batch with the same SKU label. The defense is to confirm the batch ID on your specific vial matches the batch ID on the COA. This is the fourth step in our five-step verify protocol.

Cherry-picked certificates are not caught by external verification. Even when the COA verifies cleanly against the public database, a vendor that tested only their cleanest batch is misrepresenting the average. Independent retesting on a separate batch is the only defense against this pattern. Reading public COAs alone does not catch it, and neither do our audits yet: we have not retested any vendor's vial.

Where Janoshik is located

Janoshik Analytical operates from the Czech Republic in the European Union. Its own shipping overview gives the laboratory's location as the Czech Republic, postal code 252 10 (read 15 October 2026). The public-tests database lives at public.janoshik.com; per-test verification URLs are at verify.janoshik.com. The EU location matters for the research-peptide market because it places Janoshik outside direct US regulatory pressure on the vendors they test — a structural independence that vendor-internal labs cannot offer.

How much does Janoshik testing cost?

Pricing is set per assay on Janoshik's site and varies by test type. Common services are HPLC purity quantification, LCMS identity, blind GLP-1 multi-compound tests, and full vial assessment with sterility. Vendors pay for tests they choose to submit; buyers can submit independent samples at the same fee schedule. On 15 October 2026 the common GLP-1 blind test was listed at $360; check Janoshik's site for current pricing. For a dated side-by-side of what Janoshik, Kovera and Finnrick charge and what each report proves, see peptide testing labs compared.

What this framework looks like applied to a second lab

The four-question framework above is not specific to Janoshik. We applied it to Kovera Labs, a US-facing third-party lab that began publishing COAs in early 2026. Same pattern: 1,816 published reports (May 2026 snapshot) across 145 named clients, a 0.8% explicit purity-failure rate published openly (not hidden), and a verification URL pattern that resolves to Kovera's servers rather than the vendor's.

Two independent third-party labs - one EU-based (Janoshik), one US-facing (Kovera) - clearing the same four checks is the structural argument for what "legit" actually measures here. A lab is legit when its public corpus is broad enough that no single vendor can shape what it looks like, and when failures appear in that corpus at a rate consistent with the rest of the industry. Most vendor-owned in-house QC operations do not clear that bar.

We cover the Kovera trust question in full in is Kovera Labs legit?; the Kovera mirror corpus is documented in our methodology.

Bottom line

Janoshik testing is legitimate as a third-party lab process. The data is real, the methodology is consistent, and failures are published alongside passes. The structural caveat is that the public database shows what vendors choose to publish, not what they choose to hide. Reading a single Janoshik COA is meaningful; relying on the corpus without understanding selection bias is not.

For specific verification steps when checking a single certificate, see how to verify a Janoshik COA in five steps. For the industry-level picture, see what 7,164 Janoshik tests reveal. For the lab's location, services and current public-listing numbers, see the Janoshik testing hub.

Sources

• Janoshik public tests database — the source-of-truth listing audited for this piece
• vialaudit snapshot of the Janoshik public-tests listing, 30 June 2026 (364 indexed, 337 readable)
• Janoshik help centre - general overview of the shipping process - lab location, read 15 October 2026
• Internal: How to verify a Janoshik COA
• Internal: What 7,164 Janoshik tests reveal
• Kovera Labs public verifier - second third-party lab passing the same four checks (Kovera mirror, May 2026)
• Janoshik Analytical homepage