For a research peptide, the Certificate of Analysis (COA) is often the only independent evidence you have about what is actually inside the vial. Knowing what a COA is, who produces it, and what its fields mean is a basic skill for anyone evaluating peptide vendors, whether you're a researcher, a lab purchasing manager, or a curious reader trying to make sense of vendor documentation.
What a COA Is and Who Issues It
A Certificate of Analysis is a quality-control document that reports the results of analytical testing on a specific batch of a chemical or pharmaceutical compound. It confirms whether that batch meets pre-defined specification limits for identity, purity, and other attributes.
COAs are issued by testing laboratories, of two kinds:
- In-house labs operated by the manufacturer or vendor themselves, or
- Independent third-party labs with no commercial stake in the product.
The distinction matters. An in-house COA is produced by the entity selling the product. An independent third-party COA comes from a laboratory that has no financial relationship with the vendor beyond the testing fee. A third-party analytical lab such as Janoshik Analytical is commonly cited in the research peptide community as a source of independent batch testing. Pharmaceutical-grade manufacturers such as Bachem or PolyPeptide Group publish COAs produced under certified quality systems. Bachem, for example, states its sites operate under GMP and are inspected by authorities including the FDA and Swissmedic.
A testing lab is not the same as a results aggregator. Janoshik runs the instruments and signs the COA. Platforms such as Finnrick and Peptigrity are aggregators: they procure or collate samples and publish results from a network of partner labs. Finnrick, for instance, states it works with several independent laboratories, including Krause Analytical, BTLabs, Chromate and others, rather than testing in-house.
What Fields a COA Typically Contains
A well-formed COA will include most or all of the following fields:
| Field | What It Reports |
|---|---|
| Product name / compound | The peptide or chemical being tested |
| Batch / lot number | Ties the certificate to a specific production run |
| Test date / expiry | When testing was conducted; some labs include a re-test date |
| Appearance | Visual inspection result (e.g., white lyophilized powder) |
| Purity (HPLC) | Percentage purity by High-Performance Liquid Chromatography — the core figure most buyers look at |
| Identity (MS / sequence confirmation) | Mass spectrometry confirmation that the compound is what it claims to be |
| Water content (Karl Fischer) | Residual moisture, relevant for accurate dosing in research contexts |
| Residual solvents | Checks for manufacturing solvent carry-over |
| Microbial / endotoxin | Sterility-relevant tests; not always present on peptides sold for research use |
| Pass / Fail notation | Whether the batch meets the lab's or manufacturer's specification |
The purity figure is the number most commonly cited in vendor listings. Research-grade peptides are commonly described in vendor documentation as targeting purity thresholds of 95% or higher by HPLC, though exact specifications vary by compound and intended use.
How to Tell a Real COA from a Vendor Screenshot
Not every document labeled "COA" carries the same evidential weight. A few markers separate credible certificates from superficial claims.
Indicators of a credible COA: - Identifiable issuing lab with a verifiable name, address, and accreditation number (ISO/IEC 17025 is the relevant accreditation standard for testing laboratories) - Batch/lot number that matches what appears on the product label - Raw chromatogram or spectral data attached or available on request, not just a summary percentage - Date of testing that is recent relative to the product's claimed shelf life - Contact information or a verification portal for the lab, allowing independent verification
Red flags: - A COA that shows only the vendor's own logo with no named testing laboratory - Purity figures with no associated methodology (e.g., no mention of HPLC) - No lot number, or a lot number that cannot be cross-referenced with the vendor's order records - A static image or PDF that cannot be checked against the issuing lab's records
Some independent labs make COAs verifiable at the source. Janoshik prints a unique batch reference number on each report. Enter it at verify.janoshik.com and you get back the compound name, purity, mass data and test date held on Janoshik's own servers, so a researcher can confirm a vendor's PDF has not been altered. One caveat applies regardless of the lab. In the research-peptide market, samples are typically submitted by the vendor rather than blind-purchased, so a COA verifies the tested sample, not necessarily every vial shipped.
Platforms such as Finnrick.com and Peptigrity aggregate batch-level test results that buyers can search by vendor and compound. As of early 2026, Finnrick reports having published several thousand tests across more than 200 vendors, and Peptigrity maintains a comparable public database of shop reviews and lab tests. These aggregated records let you compare vendors for the same peptide, a broader picture than any single COA gives.
Treat a COA as a starting point for quality evaluation, not a guarantee. How a lab is accredited, how samples are submitted (vendor-submitted versus blind third-party purchased), and how often a vendor tests its inventory all affect what any given document tells you. Research peptides are sold for laboratory research use only and are not approved for human consumption.
Sources
- Finnrick — independent peptide testing results
- Finnrick — partner testing labs
- Janoshik Analytical — independent peptide and chemical testing
- Peptigrity — vendor and batch quality aggregator
- Bachem — quality and regulatory
- USP (United States Pharmacopeia) — compendial quality standards
- FDA — drug quality and certificates of analysis