Certificate of Analysis

A Certificate of Analysis (CoA) is an authoritative quality assurance document generated by an analytical laboratory reporting the quantitative results of chemical, physical, and microbiological testing conducted on a specific manufactured batch (lot) of a substance. In peptide manufacturing, a detailed CoA reports appearance, identity (MS), chromatographic purity (HPLC), net peptide content (AAA), moisture, counter-ions, and bacterial endotoxin levels.

In the unregulated peptide market, CoAs are frequently falsified, copied between vendors, or misread by buyers who mistake HPLC purity percentages for actual peptide mass content.

For anyone looking at peptides sold outside the pharmacy system, the certificate of analysis is often the only quality evidence on offer. Unlike an approved medicine, a research-chemical peptide has no regulator checking that each batch contains what the label says. A CoA can fill part of that gap, but only if it is genuine, belongs to the exact batch in hand, and reports the right tests from a laboratory that can be independently identified.

The stakes are real. When researchers bought semaglutide vials from illegal online pharmacies and tested them, they found purity far below the 99% printed on the labels and detected bacterial endotoxin in every sample. A Belgian study of falsified peptide drugs bought online found low and variable purity and, in some samples, arsenic or lead. These are exactly the problems a credible, batch-specific CoA is supposed to rule out.

Reading a CoA well also means knowing its limits. An HPLC purity figure describes the proportion of peptide-related material among what the method detects. It does not by itself prove identity, net peptide content, sterility or the absence of endotoxin, which need separate tests. A CoA that reports only an HPLC percentage answers one narrow question and leaves the others open.

“A CoA means the product is safe to use”

A certificate of analysis reports test results on a batch; it is not an approval or a safety assessment. Even a genuine CoA showing high purity says nothing about whether the peptide itself has been shown to be safe or effective in people. Research-chemical peptides with impressive paperwork are still unapproved products with unknown human risk.

“99% purity means 99% of the powder is peptide”

HPLC purity measures the share of peptide-related signal that belongs to the target peptide. A lyophilised powder also contains water, salts and counter-ions such as acetate or trifluoroacetate, so the actual peptide mass, the net peptide content, is usually noticeably lower. Purity and content are different measurements and need different tests.

“Any CoA posted online belongs to what I receive”

A CoA is only meaningful for the batch (lot) it names. Generic certificates reused across many batches, documents with no traceable laboratory, or reports whose lot number does not match the vial provide little assurance. Studies of products bought online have found contents that did not match label claims.

What should a peptide certificate of analysis include?

A meaningful CoA identifies the product, batch or lot number, testing laboratory and dates. It should report identity (usually mass spectrometry), purity (usually HPLC) and ideally net peptide content, water content, counter-ions, and for injectable materials, sterility and endotoxin. Results should be shown against stated acceptance limits, with traceable signatures or accreditation details.

How can you tell if a CoA is fake?

Warning signs include a missing or mismatched lot number, no named laboratory or one that cannot be contacted, identical results across different batches, round or implausible numbers, missing chromatograms or spectra, and documents that only report HPLC purity. A CoA that can be verified directly with the issuing laboratory is far more credible than an image on a seller’s website.

Does a CoA mean a peptide is FDA approved?

No. A certificate of analysis is a laboratory test report on one batch. FDA approval is a separate regulatory decision based on clinical trial evidence of safety and effectiveness, manufacturing standards and labelling. Products sold “for research use only” are not approved for human use, whatever their CoA says, and the FDA has warned consumers not to buy such products.