How to Read a Certificate of Analysis (COA)

1. Batch Number

Every vial carries a unique batch number (e.g., PEP-BPC-240815). This number connects your vial to its specific COA. A batch represents a single production run — all vials in the same batch share the same test results. Batch numbers also enable traceability: if a quality issue is discovered, the affected batch can be identified precisely.

2. Purity (HPLC Analysis)

Purity is measured by High-Performance Liquid Chromatography (HPLC). This technique separates the compound you ordered from any impurities by passing it through a column under high pressure. The result is expressed as a percentage:

• ≥99% — Excellent. Pharmaceutical-grade purity. All impurities combined <1%.
• 98–99% — Very good. Standard for well-characterized research peptides.
• 96–98% — Acceptable for research use. Suitable for most protocols.
• <96% — Below threshold. We do not sell batches below 96% purity.

The COA will typically include the HPLC chromatogram — a graph showing the main peak (your compound) and any smaller impurity peaks. The area under each peak corresponds to its relative quantity.

3. Identity Confirmation (LC-MS)

Liquid Chromatography-Mass Spectrometry (LC-MS) confirms that the compound in your vial is actually what it claims to be. LC-MS measures the molecular weight of the compound. If the measured mass matches the expected mass (within a small tolerance), the result is Match. This is important because some counterfeit products contain a different (cheaper) peptide that happens to look similar on HPLC surface analysis.

4. Independent Verification

Every test comes with a public verification URL on the lab's platform. You can verify test results independently — visit the URL and enter the unique key provided on your COA. This prevents counterfeit COAs: if the verification page does not match your COA data, the document has been tampered with.

We link every batch on our website to its public lab result. You never have to trust us — you can verify everything yourself.

5. Additional Tests

For some batches, we include additional testing beyond HPLC and LC-MS:

• Endotoxin testing — Measures bacterial endotoxin levels. Important for sterile handling contexts.
• Heavy metals analysis — Detects lead, mercury, cadmium, and arsenic contamination.
• Sterility testing — Confirms the product is free from viable microorganisms.
• TFA content — Measures residual trifluoroacetic acid from the synthesis process.

6. Red Flags in COAs

Be cautious with suppliers who:

• Provide no COA at all — the most common issue. No testing means no quality guarantee.
• Use in-house testing only — internal labs have incentive to pass borderline products.
• Show purity without HPLC chromatogram — without the raw data, purity claims are unverifiable.
• Use a non-verifiable lab — if you cannot independently confirm results, the COA is marketing, not science.
• Reuse the same COA across multiple batches — each production run requires its own test.