Research Verification
How to read a Certificate of Analysis
A Certificate of Analysis (COA) is the single most useful document when sourcing a research compound. Here is what every field means, how to verify one at source, and the red flags that mean a report can’t be trusted.
For in vitro laboratory research only. Not for human or animal consumption; not intended to diagnose, treat, cure or prevent any condition. 18+.
A Certificate of Analysis is an independent laboratory report for one specific batch of a research compound. It states the compound’s identity, its measured purity, and its content by mass — the three things that tell you whether the material is what the label claims.
Why a COA matters more than the label
The label on a vial is a claim. A batch-specific COA from an independent laboratory is evidence. In a market where every seller states “99% pure, lab tested”, the report — and whether you can verify it — is what separates a credible supplier from marketing.
The goal when reading one is simple: confirm the vial contains the right compound, at the stated purity and amount, tested by a named third party for the exact batch you received.
HPLC vs mass spectrometry: what each measures
Two independent methods do most of the work on a COA. A good report uses both.
| Method | What it tells you | Reported as |
|---|---|---|
| HPLC High-performance liquid chromatography | Separates the sample into its components to measure purity — how much is the target compound versus impurities. | A percentage (e.g. 99.2%) |
| Mass spectrometry MS | Measures the molecule’s mass to confirm identity — that the vial contains the compound named. | Confirmed / not confirmed |
A purity figure without an identity check is incomplete: you could have 99% of the wrong molecule. Look for both.
The fields on a COA, and how to read them
Once you know what to look for, a COA takes seconds to read. Here is each field, mapped to an example.
Janoshik Analytical
Certificate of Analysis
- 01Product
- BPC-157
- 01Identity (MS)
- Confirmed
- 02Purity (HPLC)
- 99.2%
- 03Content by mass
- 10.1 mg
- 04Task no.
- JA-24-08812
- 05Lab / date
- Janoshik · 2026
- 01
Compound identity · Mass spectrometry (MS)
Confirms the vial contains the compound named on the label — the molecule’s measured mass matches the expected mass. If identity isn’t confirmed, purity is meaningless.
- 02
Purity (%) · HPLC
The proportion of the sample that is the target compound versus impurities. A higher percentage means fewer impurities; ≥99% is a common benchmark for well-made material.
- 03
Content by mass · Quantitative assay
How much of the compound the vial actually contains (for example, milligrams). It should match the labelled amount — under-filled vials are a common quality failure.
- 04
Batch / task number · Traceability
Ties the result to one specific production run and the specific test performed. A COA is only meaningful when it corresponds to the exact batch you received.
- 05
Testing laboratory + date · Provenance
Names the independent lab and when the test was done. Recent dates and a named third-party lab matter; a self-issued or undated report does not.
- 06
Verification link · Independent check
The best labs let you confirm the result on their own website, so you are trusting the laboratory — not a PDF the seller produced.
How to verify a COA at source
A PDF can be edited. The strongest COA is one you can confirm on the testing laboratory’s own website — so you are trusting the lab, not the seller. Independent labs such as Janoshik provide a report reference (and often a verification link) that lets you look the result up directly.
If a supplier’s reports can be checked at the lab, that is the strongest signal you can get. BioHack London publishes its independent reports for exactly this reason — see them here.
Red flags: when a COA can’t be trusted
- —No batch or task number — the report can’t be tied to the vial you received.
- —A single “one-off” or generic COA reused across every batch and product.
- —A report the seller produced themselves, with no independent laboratory named.
- —No way to verify the result at source (no lab reference or verification link).
- —Vague claims like “high purity” or “99%+” with no report behind them.
- —Identity not confirmed by mass spectrometry — only a purity number quoted.
Frequently asked questions
What is a Certificate of Analysis (COA)?
A Certificate of Analysis is an independent laboratory report for one specific batch of a research compound. It states the compound’s identity, its measured purity (usually by HPLC) and its content by mass. It is only meaningful when it corresponds to the exact batch you receive.
What is the difference between HPLC and mass spectrometry on a COA?
HPLC (high-performance liquid chromatography) separates the sample and reports purity as a percentage — how much of the material is the target compound versus impurities. Mass spectrometry confirms identity by measuring the molecule’s mass, so you know the vial contains what the label says. A good COA uses both: identity by MS, purity by HPLC.
What purity should a research peptide have?
As a general benchmark, look for a minimum of 99% purity reported by HPLC on a batch-specific Certificate of Analysis. A high number only matters when identity is also confirmed and the report is from an independent laboratory you can verify.
How do I verify a COA is genuine?
Check that it is batch-specific, names an independent testing laboratory, and — ideally — can be confirmed on that laboratory’s own website via a verification link or reference. If a supplier can only show a self-produced PDF with no independent lab, treat any purity claim with caution.
Who is Janoshik?
Janoshik Analytical is an independent analytical laboratory widely used to test research compounds by HPLC and mass spectrometry. BioHack London publishes Janoshik reports for its batches, and where the lab provides a verification link you can confirm the result directly with Janoshik rather than taking the seller’s word.
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