Quality · August 29, 2026

How to Verify a Peptide COA: What to Look For

A Certificate of AnalysisCOA (Certificate of Analysis)A lab document reporting what a specific batch actually contains — typically purity by HPLC and identity by mass spectrometry. Reputable research vendors publish batch-specific COAs.See glossary → is the only evidence standing between a research vial and pure faith. Every serious vendor publishes them; almost nobody explains how to read one. Here is the five-minute literacy that separates informed sourcing from label-trusting.

What a COA actually is

A COA is a lab report for a specific production batch stating what testing found: how pure the material is, and whether it is actually the claimed molecule. The two workhorse techniques:

• HPLCHPLC (high-performance liquid chromatography)A laboratory technique that separates the components of a sample to measure purity. The standard method used on peptide COAs to report a purity percentage.See glossary → (high-performance liquid chromatography) separates the sample's components and reports a purity percentage — how much of the material is the target peptide versus other substances. Research-grade material typically shows ≥98–99%.
• Mass spectrometry (MS) weighs the molecules. Every peptide has a known molecular mass; if the measured mass matches the theoretical mass, the identity is confirmed. Purity without identity is meaningless — 99% pure something is not the same as 99% pure BPC-157.

Stronger testing programs add endotoxin testing (bacterial residue relevant to injectable research) and sterility testing. A few Canadian vendors now publish these per batch — a genuinely high bar.

The verification checklist

1. Batch-specific, not generic. The COA's lot/batch number should match the number printed on your actual vial. A single evergreen COA covering "BPC-157" forever is marketing, not testing.
2. Independent lab, named. The report should identify the testing laboratory — third-party names like Janoshik are widely recognized in this space — with a report number. Some labs let you verify a report number directly on their own site: the strongest form of verification available.
3. The mass matches. Check the found mass against the theoretical mass on the report; they should agree within a small tolerance.
4. The purity is stated per batch and sits where research-grade material should (≥98%).
5. Dates make sense. A COA dated after the batch went on sale, or years before, deserves a question.
6. The quantity is tested too. Better reports confirm vial content (e.g., "5.1 mg found" for a 5 mg vial) — underfilled vials are a documented industry problem that purity numbers alone won't catch.

Red flags that end the conversation

• No COA at all, or "COA available on request" that never materializes
• Purity claims on product pages with no lab report behind them
• COAs with the lab name cropped or blurred out
• Identical purity values (say, 99.8%) across every product and batch
• A "COA" that is just an in-house spreadsheet with no lab identification
• Health claims on the same site — a vendor marketing outcomes isn't operating under research discipline, and quality claims deserve the same skepticism (see Are Peptides Legal in Canada? for why RUO framing matters)

Make it a habit

The whole check takes two minutes per order once you know the pattern: find the batch number on the vial, pull the matching COA, confirm lab + mass + purity, save the PDF. That last step matters more than it used to — as the Peptide Sciences shutdown demonstrated, vendor websites and their documentation can disappear overnight. Batch numbers and saved COAs belong in your protocol records; the tracking app has a field for exactly this.