How to Read
a COA
We break down a real Certificate of Analysis section by section — so you can tell at a glance what the sample is, how it was tested, and whether the numbers hold up.
Educational content only. A COA is a snapshot of lab testing for one specific batch — not a stamp of safety or a legal clearance. Treat it as one input in your wider sourcing checks, never the whole story.
A Real COA, Top to Bottom
Below is an actual Certificate of Analysis issued by an ISO/IEC 17025 accredited lab for a single tested batch. Every block on this page maps to a part of that report — work through them in order and you can judge any COA you are sent.
1. Who Issued It
The top of the report tells you who ran the tests and who they ran them for. A COA written by the seller themselves is a marketing sheet, not a certificate.
Independent Laboratory
A named third-party lab with a real street address, phone number and website — not an unbranded PDF.
Certificate Number
A unique COA reference (e.g. COA-2026-412955) that the lab can look up on request.
Tested For
The vendor who submitted the sample, usually with their site link. It should be the vendor you are actually buying from.
Accreditation
ISO/IEC 17025 accreditation, shown in the footer, means the lab's methods are externally audited.
2. The Summary Block
Modern COAs open with an at-a-glance summary: the compound and strength, an overall PASS or FAIL, and the four numbers that matter most. Read this first, then verify it against the detailed table further down.
Compound & Strength
For example PT-141 - 10mg. It must match exactly what the vial label and your order say.
Batch / Lot Number
#LNC2M here. This ties the report to one production run — a different lot needs a different COA.
Purity
The headline HPLC figure, 99.89% in this report. Anything under the stated specification is a fail regardless of the badge.
Mass
The measured quantity, 10.69 mg against a 10 mg label. Slightly over is normal overfill; well under is not.
Identity
Confirmed means the analysis matched the reference standard for the named compound.
Dates & Appearance
Received and analysis dates should be recent and sit close together; appearance notes the physical state of the sample.
Methods
The techniques used — HPLC for purity and quantity, PCR for sterility, USP <85> for endotoxin.
A green PASS stamp on its own means nothing. Treat it as a claim the rest of the page has to back up.
3. The Test Panel
The panel strip shows which screens were actually run. Missing panels are the real red flag — a lab can only pass tests it performed.
- Identity — the molecule is what the label says
- Purity — how much of the sample is the target compound
- Sterility — no microbial growth detected
- Endotoxins — bacterial toxin load under the limit
- Fentanyl Free — screened for fentanyl contamination
A report that only shows purity, with no sterility, endotoxin or contaminant screening, is an incomplete picture.
4. Test Results Table
This is the substance of the certificate: each test, the specification it was measured against, and the result. Check every row against its spec rather than trusting the summary.
Identity
Specification is the compound name; the result should read Confirmed.
Purity (HPLC)
Specification is a floor such as >= 95.0%. The result — 99.89% here — must clear it.
Quantity
Often Report Only, meaning it is measured but not pass/fail. Compare it to the labeled content yourself.
Sterility
No Growth (PCR) is the specification; anything else means microbial contamination.
Endotoxins (LAL)
A ceiling like <= 5 EU/mL. The result should be comfortably below, e.g. < 0.05 EU/mL.
Sample Photo
Good labs photograph the vial they tested, with the compound and lot written on it, so you can match it to what arrives.
The footnote should name the analytical method — for instance RP-HPLC with UV detection — and point to the full methodology on later pages.
5. Signature & Verification
The footer is where accountability lives. A genuine COA is signed, numbered and independently checkable.
Lab Director Signature
A named person and date taking responsibility for the analysis, not an anonymous stamp.
COA Number & Access Code
A reference plus a private access code used to pull the original report from the lab's portal.
Verification Link or QR
Scan the QR or open the verify URL. It must resolve on the laboratory's own domain and show the same batch and results.
Accreditation Marks
ILAC-MRA and national accreditation logos, with the certificate scope noted alongside.
If the verification link is missing, dead, or hosted on the vendor's own site rather than the lab's, ask for the original PDF straight from the laboratory.
Quick reference checklist
Do the product name, molecular formula, and CAS number match what you ordered?
Does the batch/lot number on the COA match the vial in hand?
Is purity clearly stated, with a result that meets the reference standard?
Did identity confirmation (LC-MS) return the correct compound?
Do endotoxin, fentanyl, and sterility screens all pass?
Are all heavy metals below their limits?
Does the chromatogram show one clean, dominant peak?
Is the report signed, numbered, and verifiable via QR or access code?