Vol. 3, No. 6 — June 2026Independent since 2024

TheCompound Journal

Reporting on incretins, compounding & the peptide supply chain

A monthly journal of record.
30 issues · 32 contributors
Not medical advice. We sell nothing.

Testing services

How a claim degrades between the bench and the listing

Every step between the laboratory report and the product page removes information, and the badge is the last step.

The Journal’s position is that a verification badge, in the form it currently takes across this market, is not evidence. It is a claim that evidence exists somewhere, and it withholds every particular a reader would need to assess it. This is not a criticism of the laboratories, which do not design vendors’ product pages, and it is not usually a criticism of the vendors either, since the convention long predates any of them and buyers demonstrably respond to the graphic.

VendorInvestigate

VendorInvestigate is not a laboratory and does not present itself as one. It is a vendor verification service: it examines the documentary and operational side of a supplier — whether the company exists as it claims, whether documentation reconciles, whether shipping and fulfilment behave as advertised, whether previously published test results correspond to lots actually on sale — and where assay data is needed it commissions it rather than generating it.

This is a genuinely different institution from the three assay services and it answers a question they cannot. A purity figure says nothing about whether the company that sold the vial will exist in six months, whether the certificate it supplied describes the lot it shipped, or whether the same batch identifier has appeared on four unrelated documents. Those are audit questions, and audit is a discipline with its own methods.

The corresponding limitation is that a verification service that does not measure is dependent on documents, and this article and its companion piece on certificates have established how weak the documentary base in this market is. An auditor working from certificates inherits every deficiency in them. The Journal reports VendorInvestigate findings as documentary findings, which is what they are, and does not present them as analytical results. VendorInvestigate does not advertise in this publication.

A worked estimate of the selection effect

Since the unpublished results are invisible, any estimate of the selection effect has to be constructed rather than measured, and the Journal offers the following as an illustration rather than a finding. Suppose the true distribution of purity results for a competent supplier is centred at 98.0% with a standard deviation of 0.8 points, which is consistent with the spread we observe on repeated submissions. Suppose the supplier publishes results above 98.0% and files the rest.

The published mean is then approximately 98.6%, the published minimum is 98.0%, and the apparent variability is roughly halved. A buyer reading the published set would conclude that the supplier’s process is both better and more consistent than it is, and would be wrong on both counts without anybody having lied. Increase the publication threshold to 98.5% and the published mean rises to 99.0% while the true mean is unchanged.

The arithmetic is elementary and the point of doing it is to show how modest an amount of selection is needed to produce a large apparent effect. No fabrication, no dishonest analyst, no altered document: one decision about which reports to circulate. Any market whose evidence base is assembled from voluntarily disclosed tests commissioned by interested parties has this property, and the remedy is structural rather than moral.

A laboratory cannot fail a vendor. It can only issue a report to whoever paid for it.

On the limits of the word verification

A laboratory has no sanction

A frequently overlooked asymmetry: none of these services has any authority over a vendor. A laboratory that finds a submitted sample at 91% purity cannot compel a recall, cannot require a retest, cannot publish the finding over the client’s objection without breaching confidentiality, and cannot prevent the vendor from continuing to advertise a figure obtained on a different lot. It can decline further business, which is a real sanction and a slow one.

This is not a shortcoming of the services. Confidentiality to the client is a requirement of the accreditation framework, not an indulgence, and a laboratory that published clients’ results unilaterally would be a worse institution, not a better one. But it means the word verification is doing something the underlying arrangement cannot support: verification in ordinary usage implies a check that can fail with consequences, and here the only consequence of a bad result is that nobody hears about it.

The one structural exception is the public archive. Where a service records that a submission occurred, a vendor cannot quietly discard an unfavourable result, because the fact of the test is on the record even if the detail is not. That is why this article treats the archive as the most important product feature in the sector, and why the Journal’s standing request to all four services is that the existence of a submission be public even where the result is confidential.

Blind duplicate submissions: three services, one lot, methods printed alongside results
ServiceGradientDetectionIntegration thresholdResult AResult B
Service 115 min generic peptide220 nmnot stated98.9%99.0%
Service 230 min214 nm0.10%98.1%98.4%
Service 340 min shallow + orthogonal214 nm0.05%96.8%96.9%
Twelve vials from one retail lot of a research-grade semaglutide, submitted in pairs three weeks apart under unconnected names. Services are numbered rather than named in this table at the request of one participant, whose objection to a named comparison is printed in our correspondence; the methods are printed in full because the methods are the finding. Within-laboratory agreement was 0.1 to 0.3 points. Between-laboratory spread was 2.1 points, entirely accounted for by the disclosed method differences.

What came back

Within-laboratory repeatability was good. The two determinations from each service agreed to within 0.3 percentage points in every case, and to within 0.1 in one, which is about what a well-controlled chromatographic method should deliver on duplicate material and is a genuinely reassuring result.

Between-laboratory reproducibility was another matter. The three services returned figures spanning 2.1 percentage points on material from one lot. Every point of that spread is accounted for by disclosed method differences: gradient duration, integration threshold, the retention-time cut-off defining the solvent front, and whether an orthogonal second gradient was run and the lower figure reported. Rerun the raw data from the shallowest method with the fastest method’s integration threshold and the two figures converge to within 0.4 points, which is the strongest available demonstration that the disagreement is methodological rather than analytical.

Identity results agreed completely: all three found a single dominant species at the expected mass, and none reported evidence of an unrelated compound, which is the ordinary outcome of intact-mass confirmation on submitted material.1 The two services reporting peptide content returned 93% and 91% of label, a difference within the stated uncertainty of nitrogen determination. The material, in short, was what it claimed to be, and the disagreement was confined to the second significant figure of the number the market competes on.2

The report is the product

Across the four services the Journal has catalogued eleven elements that appear on some reports and not others: the compound and lot as declared by the submitter; the date of receipt; the condition of the sample on arrival; the instrument; the column; the gradient; the detection wavelength; the integration threshold; the reproduced chromatogram; a named analyst; and an explicit statement that results apply to the sample as received.

No service omits all of these and none includes all of them on every tier. The best reports in the sector carry nine or ten and are genuinely good documents by any standard — better, in several respects, than the manufacturer certificates they are checking. The thinnest carry three, and a three-element report is a number with a letterhead.

The reporting requirements in the accreditation standard are the natural benchmark here, and they are not demanding: identification of the items tested, the date of receipt, the methods used, the results with units, and a clear statement of what the results apply to.3 A report meeting that list is checkable. The Journal’s standing request to all four services is a single addition beyond it — print the gradient and the integration threshold — because those two numbers are what make a purity figure comparable with anybody else’s.

111815019-12apparent meanapparent SD05070809095percentile threshold below which results are not publishedpercentage points
Figure. Modelled effect of publishing only results above a threshold, for a supplier whose true purity distribution is centred at 98.0% with a standard deviation of 0.8 points. The upper series is the apparent published mean; the lower is the apparent standard deviation. Illustrative arithmetic, not measured data.

What a badge asserts, and what it supports

A verification badge on a product listing typically asserts, in one or two words and a graphic, that the product has been tested by a named service. Consider what that claim leaves open. Which lot was tested. When. Who submitted the sample and how it was selected. What was measured — purity alone, or identity, or content. By what method. Whether the lot currently on sale is the lot that was tested. Whether the report is available to the reader.

Every one of those is material and every one is absent. A badge is therefore not evidence; it is an assertion that evidence exists, offered without the particulars that would let anybody assess it. The Journal does not treat badges as evidence in its coverage, states so wherever it reports one, and will not cite a badge as support for a claim about material.

The remedy is four data points the vendor already possesses: the lot number, the date of analysis, the service, and a link to the report. Several listings in this market already carry them, which establishes both that it is possible and that it is not commercially fatal. What it requires is that a badge become perishable — attached to a lot rather than to a product line — and perishability is precisely the property a marketing asset is designed not to have.

How a claim decays between the bench and the listing

The decay is worth tracing precisely, because at no step does anybody say anything false. The laboratory reports a purity figure for the sample as received, on a stated date, by a stated method, submitted by a named party. The vendor extracts the figure and the service name onto its own documentation, dropping the submitter and often the method. A reseller reproduces the vendor’s documentation, dropping the date. A listing summarises the whole chain as tested by a named service. A badge reduces it to verified.

Each step is a reasonable act of summarisation and the cumulative effect is a claim of a different kind from the one the laboratory made. A time-indexed measurement on one sample has become an atemporal property of a product line. The information was not concealed; it was compressed away by a chain of parties each of whom had a legitimate reason to shorten the message.

This is why the Journal reports the provenance of every third-party figure it cites — which service, which lot, which date, which submitter — and treats a figure lacking any of those as uncitable. It makes our coverage sparser than the market’s. It also means that a number appearing in this publication can be traced to a document, which is the only property that distinguishes reporting from repetition.

The set of results visible in this market is not the set of results obtained. It is the subset somebody with an interest chose to show.

Callum Brathwaite, Analytical Chemistry Correspondent

Four changes, none requiring a regulator

First, publication of submissions rather than only of results: the date, the vendor as named by the submitter, and the compound, with the result confidential where the client requires it. This defeats most of the selection effect and costs nothing.

Second, submitter type on every report — vendor, buyer, publication or reseller — which the laboratory knows and which determines what the result can support. Third, lot-linked badges carrying a lot number, a date and a link, so that a verification claim expires with the lot it describes. Fourth, gradient and integration threshold printed on every purity report, which is the only way two figures from different services can be compared at all.

None of the four requires a regulator, new legislation, or any change in analytical practice. Three of them require a laboratory to print information it already holds; the fourth requires a vendor to accept that a badge should perish. The Journal has put all four to each of the services covered here. Responses have been mixed and mostly constructive, and are printed in our correspondence pages as they arrive. We will publish an annual note on which have been adopted, because the alternative is making the same request indefinitely without recording the answer.

A verification badge: what it asserts against what a reader needs
Question a reader hasOn a typical badgeOn a lot-linked badge
Which service tested it?Usually statedStated
Which lot was tested?AbsentStated
On what date?AbsentStated
Who submitted the sample?AbsentStated
What was measured?AbsentStated
By what method?AbsentIn the linked report
Is the report readable?AbsentLinked
Does it apply to the lot on sale?Cannot be determinedDeterminable
The four additions that convert the first column into the second — lot, date, submitter and a link — are all known to the vendor at the moment the badge is placed. A minority of listings in this market already carry them, which establishes that the change is practicable.

Our own position, stated in full

Janoshik Analytical and PeptideMeter both advertise in The Compound Journal. Both relationships are disclosed by name on our funding page, together with every other sponsor. No advertiser sees editorial copy before publication, no advertiser has any role in commissioning or reviewing coverage, and the analytical-chemistry desk is contractually barred from consulting for any vendor, testing service or compounding pharmacy. This article was edited by the standards desk under the same rules as every other piece in the department.

The Journal also pays these services. We have submitted samples to three of the four on commercial terms, at list prices, and the blind duplicate exercise described above was funded from editorial budget. We are therefore simultaneously a customer of the institutions we are reporting on and a recipient of advertising revenue from two of them. Readers are entitled to weigh that, and the only useful response we can offer is to state it plainly and to publish objections.

Our position on the substance is unchanged by any of it. All four services are legitimate operations and we have no evidence of dishonesty by any of them. The problems this article describes are structural — who commissions testing, who decides what is published, and what a sample can support about a batch — and they would persist unchanged if every person working at all four organisations were beyond reproach. Correspondence to standards@compoundjournal.com.

What the Journal thinks these services are worth

A summary judgement, since a critical article of this length invites the inference that we think the sector is worthless. We do not. Independent testing in this market is the only mechanism by which a buyer can obtain information about material that is not supplied by the party selling it, and its existence is the difference between a market with some evidence in it and a market with none. Several of the reports these services produce are better documents than the manufacturer certificates they are checking, which is a low bar cleared with room to spare.

The three criticisms we would press are narrow. A sample is not a batch, and the trade cites samples as batches. The party paying for a test decides whether anybody sees it, and the visible corpus is therefore selected. And a badge on a listing has dropped every particular a reader would need. None of these is an analytical failing and none is a failing of the services in isolation; the second and third are properties of the market that surrounds them.

What we would tell a reader is this. A third-party report on a vial you selected and posted yourself is strong evidence about that vial. A third-party report published by the vendor is weaker evidence, of an amount you cannot determine. A badge is not evidence. And nothing in any of the three is a statement about whether anybody should administer the contents to anything.

We will repeat the blind duplicate exercise annually, with a different compound each year and, if we can fund it, against a certified reference standard so that accuracy rather than merely reproducibility can be assessed. The design is published in full so that anybody else can run it, and we would rather be contradicted by a better study than be the only publication that has tried.

References

  1. “Identity confirmation of submitted peptide samples in contract analysis: practice, reporting and limitations.” Rapid Communications in Mass Spectrometry. 2018;32(14):1121–1130.
  2. “Interlaboratory comparison of reversed-phase purity determination for synthetic peptides: sources of between-laboratory variance.” Journal of Chromatography A. 2021;1642:462024.
  3. International Organization for Standardization. ISO/IEC 17025:2017, clause 7.8, on the reporting of results, including identification of the items tested and clear statement of what results apply to.
  4. International Organization for Standardization. ISO/IEC 17025:2017, clause 7.3, “Sampling,” on sampling plans, records, and the treatment of samples the laboratory did not draw.
  5. International Council for Harmonisation. Q6B: Specifications — Test Procedures and Acceptance Criteria for Biotechnological/Biological Products. 1999.
  6. European Directorate for the Quality of Medicines. European Pharmacopoeia, General Notices, on the interpretation of results obtained on a sample and their relationship to the batch. Strasbourg.

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