How we test
The purchase, the blind code, the lab
Every product is purchased anonymously on the open market, with no vendor involvement and no advance notice. Samples are relabeled with blind codes and submitted to an independent ISO/IEC 17025-accredited laboratory that never sees the vendor name. We publish the result in full regardless of outcome. Vendors cannot select which products we test, cannot influence the lab or the grade, and cannot see results before publication.
The VialReport score
0 to 100. Two components. One number.
Percentage of contents that is the actual target peptide, by HPLC.
Measured content vs. label claim, in both directions. Accuracy means close to label, not simply "at least as much as promised."
Why overfill is penalized, and penalized harder than underfill
People dose off the label. If a vial labeled 10 mg actually contains 13 mg, every dose drawn from it is 30% stronger than intended, on every single injection, without the buyer ever knowing. For many compounds that is a tolerance issue. For dose-sensitive compounds, including the GLP-1 class, it is a genuine safety risk: these are titrated deliberately and slowly precisely because their side-effect burden scales with dose, and a silently overfilled vial breaks the one assumption the entire dosing schedule depends on. Underfilling costs you money. Overfilling can cost you more than that. We grade to the risk, so a large overfill is scored as the accuracy failure it is.
Letter grades
| Grade | Score range |
|---|---|
|
A |
90 to 100 |
|
B |
80 to 89 |
|
C |
70 to 79 |
|
D |
60 to 69 |
|
F |
Below 60 |
"We measured 91% purity and 14 mg in a 20 mg vial" is a fact, not an opinion, and that is the entire point.
A vial measuring 26 mg in a 20 mg label is also a fact, and a dosing risk, not a bonus.
COA integrity
Two separate assessments, reported beside the score
Every vendor publishes a Certificate of Analysis. We assess those certificates, and we report that assessment beside the score, never inside it. COA Integrity is an umbrella term for two different questions. We keep them apart, under two different names, because they can point in opposite directions on the same vial and merging them would hide that.
| COA Accuracy | Vendor Certificate Review | |
|---|---|---|
| Question | How do the numbers on the certificate compare to what we measured? | Is this certificate a trustworthy document for this specific vial? |
| Where | A row on the scorecard | A section below the scorecard |
| Access | Free on every report | Data tier and above, and in every report PDF |
| Scored | No | No |
Why they are separate
A vendor can publish a certificate whose numbers match our measurement exactly, on a document that contradicts their own label. A different vendor can publish a flawless, lot-matched, same-day certificate whose numbers bear no resemblance to the vial we received. Those are opposite problems. One name for both would force us to pick a single word for two findings, and whichever word we picked would be wrong about one of them.
COA Accuracy
We compare the certificate's stated purity and stated content against what the accredited lab measured on the vial we bought. Both figures are printed on the report so you can check the arithmetic yourself.
Content is compared to the amount the certificate itself claims, not to the number on the vial label. Measured against label is Dose Accuracy, which is already scored one row up. Running the same comparison twice would make this row restate the score instead of assessing the certificate.
The tolerances, and why they exist
Two allowances, and neither is a judgment about severity. They exist because two competent laboratories testing the same material do not return identical numbers.
Purity: 2 percentage points
Interlaboratory reproducibility on HPLC purity commonly runs one to two points. A gap inside that band is indistinguishable from measurement variation, so we do not treat it as a discrepancy.
Content: 10%
Quantitation of milligrams is noisier than purity determination, so the allowance is wider.
Beyond those bands there is a single outcome, Overstated, and the magnitude is printed next to it. We do not publish a severity ladder. There is no analytical basis for a cutoff that would separate a large gap from a very large one, a threshold like that creates a cliff where a vendor just under it gets a gentler word than one just over it for no reason a reader could justify, and the number tells you more than any adjective we could attach to it.
What a gap does, and does not, establish
A vendor certificate is almost always run on a different physical vial from the one we bought, drawn from the same lot. Lots are not perfectly homogeneous. So a gap between a certificate and our measurement does not by itself establish that the certificate was wrong on the day it was issued.
That explanation carries real weight on a small gap and very little on a large one. A two or three point purity difference is the kind of thing ordinary batch variation produces. A thirty point difference is not, and neither is a vial holding thirty percent less than the certificate states.
We say this once, here, rather than on every report. A report shows the certificate's number and our number. Printing the vendor's most likely rebuttal beside every finding would read as arguing their case for them, and it would dilute the serious gaps in order to soften the minor ones. The tolerance bands already absorb ordinary variation. What clears them is what we publish.
Understating is never a finding
If a certificate claims less than we measured, the outcome is Matches. A vendor is never marked down for being conservative about their own product. This is the same principle that governs the score: honesty is never penalized.
That does mean a vial can carry a clean COA Accuracy result and a poor Dose Accuracy score at the same time. A certificate claiming 9 mg on a vial we measure at 12.5 mg against a 10 mg label is an accurate certificate and an overfilled vial. Both statements are true, and both appear on the report.
Vendor Certificate Review
Separately, we assess whether the certificate is a trustworthy document for the vial in our hands. This section states facts about the document and lets you draw the conclusion. It makes no claim about anyone's intent, and it is not part of the score.
Four checks, each reported in plain language beneath a single summary line:
Provenance
What kind of certificate it is: third-party and batch-specific, the vendor's own laboratory and batch-specific, generic and not tied to any batch, or none at all. We name the issuing laboratory here, and only here.
Batch and lot match
Whether the lot printed on the certificate matches the lot on the physical vial. Where a vial carries no lot number at all, we say so rather than leaving it blank.
Recency
The gap between the certificate date and the order date. This is an observation, never a disqualification. An older certificate can still be the correct one for the batch shipped.
Internal consistency
Whether the certificate agrees with the vendor's own label. A certificate reporting 13 mg on a product sold as a 10 mg vial contradicts the label the buyer doses from, regardless of what we measured.
What we do not do here
We do not rank laboratories. Provenance describes what a certificate is, not how much you should trust whoever issued it, and we do not publish trust ratings on outside labs in either direction.
We also do not characterize how a certificate came to exist. A vendor who ships a lot other than the one tested produces the same numbers as a vendor who never tested at all, and the document in front of us cannot tell those apart. We publish the gap and the document facts. Anything beyond that would be a guess wearing the clothes of a finding.
Identity verification
Where substitution risk is high, we confirm the molecule itself, not just its quality.
LC-MS confirmed
Molecular weight verified by mass spectrometry. Used on high-substitution-risk compounds.
Retention-time consistent
Sample elutes with a certified reference standard by HPLC, a consistency check, not definitive mass-based confirmation. This is our standard confirmation and is what most accredited peptide panels include.
Where both are run and disagree
The mass-based result governs, and the disagreement is published. A sample that matches on retention time but fails by mass is a more serious finding than a plain failure, not a lesser one.
Identity is a gate, not a scored metric. When identity is not confirmed, the quality grade is suppressed entirely. There is no letter, no number, and no F. The measurements are reported as raw values with no grade attached, because a vial that is not the labeled compound has nothing coherent to grade. COA Accuracy reads Not assessable for the same reason.
We do not grade samples that were not the compound.
This is why a vendor's graded count and tested count can differ: a sample that failed identity is excluded from the quality average but stays in the identity record permanently.
Safety screen
A separate finding, not part of the launch scope.
We are not running contamination assays at launch, so no safety result appears on a report unless a real screen was performed for that specific product. We do not run every assay on every sample, and we never imply an assay was run when it was not. When we do add safety screening, it will cover:
Heavy metals and residual solvents are not currently part of our panel. Where an assay was not run, the report says so by name; a panel that was not run is absent from the report, never assumed to pass.
Why we keep it separate
Safety findings are reported separately and are never folded into the 0-to-100 score. Safety is not run on every sample, and mixing a sometimes-tested result into the score would make grades mean different things on different reports. A product can be 99% pure and still carry contamination, because purity and safety measure completely different things. Keeping safety separate means a VialReport score means exactly the same thing on every product we cover, while safety-screened products carry visible, additional proof.
Scope
What the score includes. What it does not.
The 0-to-100 score is measured product quality only: purity and dose. COA Integrity, Identity, and Safety are reported as separate, clearly labeled verifications rather than blended into the number. They are not measured identically on every sample, and folding them in would break the one thing that makes a grade trustworthy: that it means the same thing every time. A vendor can deliver a clean, accurate product and still earn a transparency mark for refusing to publish a verifiable COA. Those are different questions, and we keep them visibly separate so you can weigh them yourself.