Janoshik's public database held 68 retatrutide and 48 tirzepatide reports in our 30 June 2026 snapshot. Every one confirmed the labelled compound. Median purity was 99.78% for retatrutide and 99.81% for tirzepatide, and none fell below 99%. Fill ran high: the median vial held 110% (retatrutide) and 113% (tirzepatide) of its label. One retatrutide vial held 87.8%. Vendors choose which reports go public, so treat this as the best case.
Our 30 June 2026 snapshot of Janoshik's public database holds 68 retatrutide reports and 48 tirzepatide reports. All 116 confirmed the labelled compound, and purity sat between 99.04% and 99.97%. The labels missed high: the median retatrutide vial held 110% of its stated mg, the median tirzepatide vial 113%. One retatrutide vial held 87.8%.
Vendors chose to make these numbers public. Janoshik tests whatever a client sends, and the client decides whether the report goes into the public listing, so read every figure here as the best case the market is willing to show.
What do Janoshik's public retatrutide and tirzepatide reports show?
| Retatrutide | Tirzepatide | |
|---|---|---|
| Public reports in snapshot | 68 | 48 |
| Analysis dates | 4 Feb 2025 to 23 Jun 2026 | 30 Sep 2024 to 23 Jun 2026 |
| Reports dated Jan to Jun 2026 | 58 | 37 |
| Distinct client names | 43 | 30 |
| Identity confirmed | 68 of 68 | 48 of 48 |
| Reports with a label and a measured mg | 60 | 43 |
| Median % of label (IQR) | 110.4% (106.2 to 112.9) | 112.7% (107.8 to 114.3) |
| Lowest / highest % of label | 87.8% / 143.5% | 98.8% / 127.8% |
| Under 90% of label | 1 | 0 |
| Over 110% of label | 33 | 27 |
| Median purity (IQR) | 99.78% (99.62 to 99.85) | 99.81% (99.75 to 99.87) |
| Lowest purity | 99.04% | 99.39% |
Percent of label is measured mg divided by the mg printed on the sample name. Eight retatrutide and five tirzepatide reports drop out of that column: seven samples (four retatrutide, three tirzepatide) had no label size, three retatrutide pens were reported in mg per ml, one retatrutide report was a qualitative LC-MS screen, and two tirzepatide samples named "T100" and "T120" came back without an mg figure.
Our earlier Janoshik analysis cites a 43% rate of samples failing their label purity claim in Janoshik's 2024 testing, a much wider pool that includes private submissions. That piece also cites a 2025 report that roughly 23% of retatrutide samples sent to Janoshik held exendin-4 analogues instead. None of that shows up in the public subset, because a vendor with a wrong-compound result has no reason to publish it.
How full were the vials?
Mostly overfilled. Of 103 reports with a label and a measured mg, 7 came in under 100%.
| Label | Retatrutide n | Median % of label | Tirzepatide n | Median % of label |
|---|---|---|---|---|
| 5 mg | 2 | 111.2% | 0 | |
| 10 mg | 18 | 109.8% | 6 | 111.6% |
| 15 mg | 1 | 117.9% | 3 | 117.0% |
| 20 mg | 16 | 112.0% | 10 | 114.3% |
| 30 mg | 14 | 109.9% | 10 | 112.8% |
| 40 mg | 5 | 110.7% | 2 | 120.1% |
| 50 to 60 mg | 4 | 102.3% | 8 | 107.8% |
| 100 to 120 mg | 0 | 4 | 112.4% |
An overfill is still a labelling error. A vial sold as 10 mg that holds 14.35 mg has a label that is wrong by 44%, and anyone comparing price per mg across vendors is using the wrong denominator. Finnrick's default standard passes fill within plus or minus 25% of the label; three reports in this set sit outside that band, all on the high side (peptide testing labs compared covers the standards).
What about purity?
Every quantified report cleared 99%: 55 of 67 retatrutide and 47 of 48 tirzepatide reports cleared 99.5%. HPLC purity is the target peak's share of peptide signal. It says nothing about water, salts, endotoxin or milligrams in the vial, so the fill column tells you more than the purity column here. Our endotoxin explainer covers the test none of these reports included.
Which results stand out?
| Report | Client as printed | Sample | Result | Note |
|---|---|---|---|---|
| 102150 | Arctic Lab Supply | retatrutide 10 mg, batch RT-2501-A | 8.78 mg (87.8%), 99.610% | only result under 90%; Janoshik comment: "Sample was tested twice."; analysed 26 Feb 2026 |
| 97073 | RetaEU.nl | retatrutide 10 mg, batch 74382 | 9.36 mg (93.6%), 99.855% | January 2026 |
| 97074 | RetaEU.nl | same batch, LC-MS screen | "mannitol, retatrutide, and degradation products" | qualitative, so no amount |
| 91618 | Crystal Peptides | retatrutide 10 mg | 14.35 mg (143.5%) | largest overfill; December 2025 |
| 153029 | NouvePen | tirzepatide 40 mg in 3 ml | 51.12 mg (127.8%) | a cresol preservative peak was not counted as an impurity |
Why do some reports share identical figures?
20 of the 116 reports sit in groups with the same result to the hundredth of a mg. The largest groups date from 14 April 2026: six retatrutide 20 mg reports under six client names (vicopeptide.com, hkuppeptide.com, taikangbio.com, taishijie.com, zjpeptix.com and peptiatlas.com) all read 22.39 mg and 99.818%, and six tirzepatide 20 mg reports under the same names read 22.86 mg and 99.81%. Four pairs follow the same pattern, for example Qihang Peptide and YH Peptide on tirzepatide 60 mg (64.69 mg, 99.901%).
Matching figures at that precision point to one tested sample per group. Janoshik sells an "Additional Report", a copy of one result with a different client name, manufacturer or batch in the header, at $50 a copy, and buyers also split group tests. The reports do not show which arrangement applies, or which name made the material. We have not asked Janoshik or these sites. Counting each group once leaves 62 retatrutide results (median 109.9% of label) and 40 tirzepatide results (median 111.8%), so the headline figures hold. Our shared COA URLs analysis covers the same pattern on vendor sites.
What else should you check on a report?
- The batch field. The six retatrutide reports above list the batch as "2026", which identifies no lot.
- Vendor overlays. The retatrutide report from the vendor we review as CertaPeptides carries an overlay reading "99.7% Purity. Independently Verified."; the underlying figure is 99.702%. Overlays are vendor marketing, not part of Janoshik's report.
- Code names. Several samples use catalogue codes: "GLP-3 R 30mg" and "GLP-1 T 120mg" (Penguin Peptides), "GLP-3RT 20mg" (MaximumPeps), "RT30", "TR60". Janoshik's blind test identified the compound each time. Our note on code-name catalogues explains why sellers use them.
Which vendors published the most reports?
Names are as printed on the public reports, grouped where one vendor used two spellings. Publishing reports is not a recommendation, and we have not audited most of these sellers.
| Vendor as printed | Retatrutide | Tirzepatide | Region named on report |
|---|---|---|---|
| InnoPeptide | 8 | 4 | US |
| Modern-Peptides.com (Modern Research LLC) | 6 | 4 | US and Canada on some reports |
| PeptideGurus | 4 | 4 | US, UK, EU on most reports |
| Crystal Peptides EU | 4 | 1 | EU |
| Longevity Pro's | 4 | 3 | none |
| Cocer Peptides | 3 | 3 | none |
| Apex Pharma.io (pens) | 3 | 0 | none |
| zztai Peptide Ltd | 1 | 3 | none |
| Qihang Peptide | 1 | 2 | none |
| Penguin Peptides | 1 | 2 | none |
InnoPeptide published one retatrutide report for each size from 10 to 60 mg on 7 May 2026, between 103.0% and 107.1% of label. A report for every size tells you more than one report on a vendor's best seller.
Where do these vendors ship from?
Most reports do not say: 42 of 68 retatrutide and 38 of 48 tirzepatide reports carry no region in the client or sample line. Where a region appears (some reports name more than one), the US leads (15 retatrutide, 8 tirzepatide), then the EU (12 and 5) and the UK (4 and 4). Canada appears on 3 retatrutide reports and China on one. We count a report toward a region only when it names one, not from "Ltd" or factory wording in the client name.
How do you look up a Janoshik public test yourself?
- Find the task number and unique key. Each report prints a task number at the top (for example #102150) and a 12-character unique key at the bottom.
- Open the record on Janoshik's server. Go to verify.janoshik.com/tests/ followed by the task number, or enter the key at janoshik.com/verify. Check the domain before following a link a vendor gave you.
- Match the fields. Client, sample name, manufacturer, batch and analysis date must match the copy you were shown. A mismatch on any field means the copy is not this report.
- Work out percent of label. Divide the measured mg by the label mg. 8.78 mg on a 10 mg label is 87.8%.
- Match the batch to your vial. A report on batch RT-2501-A says nothing about a vial with a different batch.
To browse, open public.janoshik.com and search the sample name, for example "retatrutide". Task numbers appear to follow the order date, not the analysis date: report 137804 was ordered on 24 March and analysed on 14 April 2026, the same day as reports numbered 147610 and above, so a low number on a recent report is normal. Our four-step verification guide covers forged and edited copies, is Janoshik testing legit covers what the public database proves, and the Janoshik hub collects the rest.
What can't this data tell you?
Selection. Clients choose what to publish, and a vendor with a failed batch can keep that report private. Zero identity failures in 116 public reports is what that filter would produce; it is not evidence that the market has none.
One sample per report. Each report covers the vial that reached the lab, not the next batch or the vial in your hand.
Endotoxin and sterility. None of these 116 reports included either result. Janoshik sells both as add-ons (endotoxin at $180 on the GLP-1 test page in October 2026).
Our extraction. We read each report image into structured fields and re-checked the outliers named above against the images; elsewhere a misread digit is possible. The snapshot ends 30 June 2026, and Janoshik has issued many GLP-1 reports since.
What we read
Janoshik's public listing at public.janoshik.com and the 116 retatrutide and tirzepatide report images in our 30 June 2026 mirror, with the outliers re-opened at verify.janoshik.com on 9 October 2026; Janoshik's GLP-1 blind test price page and help centre; our earlier Janoshik and lab-comparison articles.
What we did not read
Reports published after 30 June 2026. Three listing entries whose report pages did not render for our extractor (two retatrutide-coded, one tirzepatide-coded). Private Janoshik results. Any vendor's own explanation for the identical-figure reports. We did not contact Janoshik or the vendors named.
Sources
- Janoshik public tests listing, mirrored 30 June 2026
- Janoshik report 102150, Arctic Lab Supply, retatrutide 10 mg, 8.78 mg, re-opened 9 Oct 2026
- Janoshik report 97073 and 97074, RetaEU.nl batch 74382
- Janoshik report 91618, Crystal Peptides, 14.35 mg on a 10 mg label
- Janoshik report 153029, NouvePen, tirzepatide 40 mg
- Janoshik report 147610, one of six identical retatrutide 20 mg results, 14 Apr 2026
- Janoshik, common GLP-1 peptide blind test ($360; endotoxin add-on $180; checked 9 Oct 2026)
- Janoshik help centre, additional services ("Additional Report" copies with a different client name)
- Finnrick, methodology (fill tolerance)
- Related: retatrutide, tirzepatide, retatrutide vs tirzepatide
Frequently asked
What are the results of the Janoshik test for retatrutide and tirzepatide?
In our snapshot of Janoshik's public database (to 30 June 2026), all 68 retatrutide and 48 tirzepatide reports confirmed the labelled compound. Purity medians were 99.78% and 99.81%. Measured content usually exceeded the label: median 110% and 113%. One retatrutide 10 mg vial held 8.78 mg, the only result under 90%.
Where can I get my retatrutide tested?
Janoshik in the Czech Republic runs a GLP-1 blind test that identifies semaglutide, tirzepatide or retatrutide and reports mg and purity; it listed the test at $360 in October 2026. US buyers can also use Finnrick or Kovera. Our labs comparison covers price, turnaround and how each result can be checked.
How to verify a Janoshik retatrutide or tirzepatide report?
Take the task number and the unique key printed at the bottom of the report. Open verify.janoshik.com/tests/ followed by the task number, or enter the key at janoshik.com/verify. Match sample, batch, client and analysis date to the copy you were sent, then match the batch to the vial you hold.
Which peptide companies use Janoshik for tirzepatide and retatrutide?
In our snapshot, 43 different client names published retatrutide reports and 30 published tirzepatide reports. InnoPeptide, Modern-Peptides.com, PeptideGurus, Crystal Peptides, Longevity Pro's and Cocer Peptides published the most. A long list of reports is not a quality ranking: each vendor picks which results to publish.
How long does Janoshik take to test a GLP-1 sample?
For the 77 reports in this set that print both dates, the median gap from sample receipt to analysis was 4 days, with a range of 0 to 9. That excludes shipping to the Czech Republic and customs, which add a week or more for buyers outside the EU.
Does a passing Janoshik report mean the vial I bought matches it?
No. A report covers the sample that reached the lab. Vendors choose which samples to send and which reports to publish, and a later batch can differ. Check that the batch code on the report matches the code on your vial, and treat reports with a generic batch such as "2026" as weak evidence.