How We Score COAs
Every Certificate of Analysis submitted to VialTalk is evaluated across five categories. Each COA receives an individual score (0–100), and vendors earn an overall letter grade based on the average of all their approved COAs.
Purity
Highest WeightThe reported purity percentage from analytical testing (typically HPLC or LC-MS). Higher purity means a higher score. This is one of the two most important factors — it directly reflects product quality.
A peptide tested at 99%+ purity scores significantly higher than one at 90%.
Weight Accuracy
Highest WeightHow closely the tested product weight matches what the buyer was promised. Underdose (getting less than labeled) is always penalized. Overfill (getting more than labeled) is treated as neutral by default, and can earn full credit when a vendor labels the vial at the true fill and an admin has verified their dose documentation — transparency is rewarded. Missing weight data doesn't count against a vendor, it just doesn't earn the category.
A vendor labeling 10mg and testing 9.4mg (−6% underdose) takes a penalty. A vendor labeling 10mg and testing 10.6mg (+6% overfill) scores well even without proof; a vendor labeling their vial at 11.5mg and testing at 11.5mg — with admin-verified dose proof — earns the full 35/35.
Lab Credibility
High WeightWhich third-party laboratory performed the testing. Labs recognized as gold-standard by the peptide research community score highest. All COAs must use third-party testing — in-house testing is not accepted.
Using a well-known, community-trusted lab like Janoshik Analytical or ILS Laboratories earns top marks.
Documentation
Medium WeightCompleteness of the COA documentation. We check for product name, batch number, test date, testing method, and whether the actual COA document was provided.
A COA with all fields filled in and the document attached scores higher than one missing key details.
Bonus Testing
Bonus (Not Required)Extra tests that go above and beyond standard analysis. These are NOT required — a vendor can earn an excellent grade without them. But vendors who invest in comprehensive testing are rewarded.
Residual solvent testing, endotoxin testing, mass spectrometry confirmation, and expiration dates all earn bonus credit.
Grade Scale
Your overall vendor grade is calculated from the average score of all your approved COAs. Early grades are marked as "Preliminary" (1 COA) or "Developing" (2–4 COAs) to reflect that the grade becomes more reliable with more data.
Volume builds the grade
Submitting more approved COAs lifts your overall score a little bit, capped at +5 points. The bump follows a diminishing-returns curve — one COA adds nothing, five adds +2.5, ten adds +4, and twenty-plus caps at the full +5. Quality still dominates: you can't coast on volume if your individual scores are weak.
What the public sees
Every approved COA is scored the same way regardless of vendor tier. What changes between tiers is how much of the scoring data is displayed on the public vendor listing.
- Free tier: shows the product name, lab, purity, and test date. Weight accuracy delta and the COA Quality Grade are hidden; a paywalled upgrade CTA appears in place of the grade.
- Verified, Featured, Elite: full display — COA Quality Grade, overall score, weight accuracy delta, and the per-COA score ring.
Third-Party Testing Required
All COAs submitted to VialTalk must come from a recognized third-party testing laboratory. In-house or self-testing is not accepted. This ensures that every score on VialTalk reflects independent, verifiable quality data.
Our Scoring Principles
New to COAs? Read about COA verification →
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