COA Field Guide
How to Read
a Peptide COA.
Know what each field tells you. Match the batch, read the reported tests, and check the certificate with the issuing laboratory.
Read the record. Field by field.
A Certificate of Analysis records the tests reported for a particular sample or batch. Formats and testing panels vary. Use the fields below as a reading guide, not as a specimen certificate.
01
The lab
Look for
Independent laboratory name
An independent, named laboratory is what makes a certificate checkable by someone other than the vendor. No named lab — no verification, just a PDF.
02
Batch number
Look for
Batch / lot identifier
The lab's own identifier for the synthesis run, recorded exactly as issued. Match it to the batch on the product listing — that link is what makes a COA batch-matched. Lot vs batch →
03
Test date
Look for
Date of analysis
When the analysis ran. A current batch carrying a years-old certificate is a mismatch worth questioning.
04
Identity
Look for
Identity result + method
Mass-spec confirmation that the material is the compound on the label. Everything else on the certificate is meaningless if this line is missing — purity of the wrong molecule is not purity.
05
Purity
Look for
Purity result + HPLC method
The fraction of peptide content that is the target sequence (HPLC). Read it with its context: a % without a method, lab, and batch number can't be compared with one that has all three. And purity describes composition, not the amount in the vial —
06
Label claim
Look for
Tested quantity + labeled quantity
— that's this line: tested quantity against the labeled amount. Underfilled vials are a documented problem in this market; a certificate that never states tested quantity leaves the question open.
07
Endotoxins
Look for
Endotoxin result + reporting units
Bacterial byproducts that survive filtration and are invisible in a clean-looking vial. For research work they're a confound — able to alter results independently of the compound under study.
08
Contamination panel
Look for
Individual screening results
Sterility (viable microbes), heavy metals (synthesis residues), and a fentanyl screen (a statement about the lab's cross-contamination discipline). Purity alone tests the molecule; this panel tests the material. What each panel covers →
Batch-matched or just marketing?
✓ Batch-matched COA
Tied to the specific synthesis run your vial came from — the batch number on the certificate corresponds to the batch on the listing. Tells you about your vial. Every Forge listing links the certificate for the batch actually in stock.
✗ Brand-level COA
One undated certificate for some batch the vendor once tested, shown as representative of everything they sell. Tells you about a vial that may have shipped years ago. That's a marketing image, not verification.
Check your certificate in four steps.
01
Open the COA linked to the current batch on the product listing.
02
Match the batch or lot identifier on the certificate to the listing.
03
Read the reported tests, methods, results, and test date.
04
Use the issuing lab’s verification route and the report code to check the original record.