How to Verify a Peptide COA
A test result does not establish that any substance is safe or suitable for human use. PeptideToolsHub does not sell, source or recommend peptides or vendors.
A certificate of analysis (COA) is a laboratory's report on one specific sample. It's only useful if it's genuine, matches the batch in question, and measures what it claims to. This guide covers what a COA should contain, common red flags, how to confirm a report with the issuing lab, and what ISO/IEC 17025 accreditation does and doesn't mean.
To find labs and their verification portals, see our Check product testing section, the lab comparison and our list of public peptide test databases.
What a peptide COA should contain
ISO/IEC 17025, the international standard for testing laboratories, lists what a test report should include. Not every peptide lab works to it, but the list is a useful baseline.
- Lab identity and contact details. The lab's name and address, and where the testing was done. You should be able to find the same lab on an independent website.
- Sample ID and batch or lot. A unique report or sample ID, a clear description of the item, and a batch or lot number that matches the product label. A COA applies only to the sample tested, and the standard asks for a statement saying so.
- Test methods. Each result should name its method (see below).
- Results, with units. Look for clear purity, identity and, where stated, quantity results.
- Chromatograms and spectra. The HPLC chromatogram and, where mass spectrometry was used, the mass spectrum show the raw data behind the numbers.
- Dates. When the sample was received, when it was tested and when the report was issued.
- Signatures and authorization. Who authorized the report. The standard requires results to be reviewed and authorized before release.
HPLC-UV vs LC-MS: what each establishes
- HPLC-UV (liquid chromatography with UV detection) separates a sample's components and is the standard way to assess purity. Several significant peaks suggest synthesis side products. A single main peak doesn't by itself prove the peak is the expected peptide.
- LC-MS (liquid chromatography with mass spectrometry) measures molecular mass, showing which peak is the expected peptide. That's how identity is confirmed. Tandem MS (LC-MS/MS) can also confirm the amino acid sequence.
Purity vs identity vs quantity
- Identity: is the expected compound present? This usually needs MS.
- Purity: what share of the detected material is that compound? This usually comes from HPLC-UV.
- Quantity or content: how much is there? Some reports give an amount per vial. “Net peptide content” is a percentage that excludes water and counter-ions.
A high purity figure with no identity test shows the sample is mostly one compound, but not which compound.
Red flags
- No lab contact details, or a lab name you can't find anywhere else.
- Edited or altered PDFs: mismatched fonts, misaligned or blurred numbers, or details that differ from the lab's own copy. PDFs can be modified, so the lab's original record is the stronger check.
- Mismatched batch numbers: the COA's batch doesn't match the label, or there's no batch identifier at all.
- No verification lookup: no report code, QR code or other way to confirm the report with the lab.
- Identity claimed with HPLC-UV alone and no reference standard named. Matching a reference standard's retention time is weaker evidence of identity than a mass-spectrometry result.
- An accreditation logo with no certificate number or accreditation body.
How to confirm a report with the issuing lab
- Find the lab's official site yourself, not through a link supplied with the COA. Our Check product testing section links to official sites.
- Open its verification portal. Look for a “Verify” or “COA lookup” page, or scan the report's QR code if it has one. The comparison page shows which listed labs offer one, and our public test databases page lists the portals we've confirmed.
- Enter the identifiers exactly as printed, such as a report or task number plus an access key, or a search code. Some portals are case-sensitive.
- Compare the lab's copy line by line: sample, batch, dates, methods, results and chromatograms. At least one lab states that a report counts as legitimate only if it matches the version stored in its system.
- If it doesn't verify, treat the report as unconfirmed and contact the lab using details from its official site. Even a report that verifies only shows that the lab issued it for that sample; it doesn't make any product safe or suitable for human use.
Some testing services deliberately leave the vendor name or batch ID off their certificates and expect you to get those details from the requester. On those certificates a missing batch ID isn't by itself a sign of tampering, but the report still can't show that it relates to your batch. Read each portal's own instructions.
What ISO/IEC 17025 accreditation does and doesn't mean
What it means: an accreditation body has assessed the lab's competence against ISO/IEC 17025 and issued a certificate plus a scope of accreditation listing the specific test methods covered. Accreditation is reassessed periodically.
What it doesn't mean:
- It isn't blanket approval. Only the tests and materials in the scope are covered. A lab can be accredited for cannabis testing and still run peptide tests outside its scope. Even a scope that includes peptides may list only certain named peptides and a single technique, such as HPLC without mass spectrometry.
- It isn't product certification. It doesn't certify any product or result as safe.
- ISO 9001 isn't the same thing. ISO 9001 certification on its own doesn't show a lab can deliver technically valid results, and “compliant with ISO principles” isn't accreditation.
To check a claim: find the accreditation body and certificate number. Look the lab up in that body's own public directory. Confirm that the scope lists the specific peptide test and method on your COA, and check that the accreditation is current and covers the testing site. ILAC's website lists recognized accreditation bodies by country.