How to Read a Certificate of Analysis for a Peptide Supplement
The peptide market has no centralized quality assurance authority. Unlike pharmaceutical drugs, research chemicals are not subject to FDA manufacturing standards. The result is significant variance in product quality across suppliers, and the only tool you have as a consumer to evaluate that quality is the certificate of analysis.
A COA is only as useful as your ability to read it. Here is what each section means and what to look for.
Educational content only. Not medical advice. Consult a healthcare provider before using any supplement or research chemical.
What a Certificate of Analysis Is
A certificate of analysis (COA) is a document issued by a testing laboratory that reports the results of specific analytical tests performed on a sample of a product. For peptides, it should confirm the identity of the compound, its purity, its concentration, and the absence of specific contaminants.
A COA from a reputable third-party laboratory is the most meaningful quality signal a peptide supplier can provide. First-party COAs, testing done by the manufacturer on their own products, are less reliable because there is a conflict of interest.
What to Look for in a COA
Identity Confirmation by Mass Spectrometry
Mass spectrometry (MS) confirms the molecular identity of the compound. The test reports a molecular weight that should match the known molecular weight of the peptide. For BPC-157, the molecular weight is approximately 1419.53 g/mol. For KPV, it is approximately 340.38 g/mol. A COA without mass spectrometry confirmation has not verified what the compound actually is.
Purity by HPLC
High-performance liquid chromatography (HPLC) measures purity by separating the components in a sample and measuring the proportion that represents the target compound. For research-grade peptides, you should expect purity of 98 percent or higher. Anything below 95 percent is worth questioning.
Batch-Specific Testing
The COA should reference a specific lot number or batch number that matches the product you have. A generic COA not tied to a specific batch is not meaningful quality assurance. Suppliers who test once and reuse the COA for all future production are not providing real quality verification.
Endotoxin Testing
Endotoxins are bacterial byproducts that can cause severe inflammatory reactions when introduced into the body. For any peptide intended for internal use, the COA should include endotoxin testing confirming levels below a safe threshold. The absence of endotoxin testing is a significant red flag.
Testing Laboratory Accreditation
The laboratory that issued the COA should be accredited. ISO 17025 is the international standard for testing laboratory competence. An accredited laboratory follows validated methods, uses properly calibrated instruments, and is subject to external audits.
Red Flags
- No mass spectrometry confirmation of identity
- HPLC purity below 95 percent
- No lot number or batch reference on the COA
- COA issued by a lab with no verifiable accreditation
- COA dated significantly before the product was purchased
- No endotoxin testing for a product intended for internal use
- Supplier unwilling to provide the COA before purchase
Frequently Asked Questions
What is a certificate of analysis?
A COA is a document from a testing laboratory reporting the results of analytical tests performed on a specific product batch. For peptides, it should include identity confirmation by mass spectrometry, purity by HPLC, and endotoxin levels.
How do I verify a COA is legitimate?
Look for the laboratory's name and check whether they are ISO 17025 accredited. Accredited laboratories can be verified through the ILAC database. Ask the supplier for the lab's contact information and verify the COA directly with the lab if you have doubts.
What purity should a research peptide have?
For research-grade peptides, 98 percent purity or higher is the standard. Anything below 95 percent suggests significant impurities that may affect both the safety and the research utility of the compound.
Disclaimer: Educational content only. Not medical advice. FeelGoodPeptide products are sold as research chemicals and are not intended to diagnose, treat, cure, or prevent any disease. Consult a qualified healthcare provider before using any supplement or research chemical.