A certificate of analysis (COA) is a document reporting specified test results for a stated sample or lot. Use it as one piece of documentation and read it in light of the methods and scope shown on the report. A COA is not, by itself, proof of safety, efficacy, sterility, regulatory approval, or the contents of every unit in a lot.
What to check on a COA
- Product and lot: Compare the product name, lot number, and any sample identifier with the corresponding listing and label.
- Issuer and date: Identify who issued the report, when the sample was tested, and whether the issuer can be contacted through independently verified details.
- Methods and results: Look for the analytical method, reported result, units, and relevant conditions. A result without method context is difficult to interpret.
- Scope: Check which tests were performed and which attributes were not tested. Do not assume that a COA includes tests that are not listed.
HPLC and mass spectrometry provide different information
Chromatography can separate detected components and report results under a particular method. A chromatographic area percentage should not automatically be treated as total peptide content, potency, or proof of identity. Mass spectrometry can provide useful molecular-mass and identity evidence, but its interpretation also depends on the method and sample. Research on peptide quality describes the use of multiple analytical techniques, including chromatography and mass spectrometry, to evaluate different quality attributes.
See the peer-reviewed reviews on reference standards and synthetic peptide quality and LC-MS characterization and its pitfalls.
Limits of a COA
A COA does not automatically verify the authenticity of its issuer or establish that the tested sample represents every unit sold. It also does not establish sterility, suitability for an experiment, safety for people or animals, or FDA approval. Third-party testing may add information, but it does not remove the need to review the test scope, method, sample identity, and report provenance.
Research-use boundaries
Research-use-only wording does not make a product appropriate for human use or establish a product’s legal status. FDA has warned about unapproved GLP-1 drugs, including products sold with research-use-only language but intended for human use. Read FDA’s consumer alert. This guide does not provide medical advice, dosage, preparation, or administration instructions.
Peptides Skin documentation
Peptides Skin sells research materials discussed on this site. Product-specific documents and lot details should be reviewed against the item and lot supplied. A supplier-provided document is not an independent guarantee; contact the named issuer if you need to verify its origin or scope.
References
- Reference Standards to Support Quality of Synthetic Peptide Therapeutics
- Characterization of Synthetic Peptide Therapeutics Using LC-MS
- FDA: Concerns with unapproved GLP-1 drugs
Frequently Asked Questions
Does a COA prove safety or approval?
No. A COA reports selected results for a specific lot; it is not FDA approval and does not establish clinical safety or efficacy.
Should the lot number match the vial?
Yes. The lot on the certificate should match the material being reviewed so the record is traceable.
Does HPLC alone confirm identity?
No. HPLC purity and identity testing answer different questions; review the listed methods together.