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What Is a Certificate of Analysis (COA)?

By BioLabs Research · Last reviewed October 2026

A plain-language explanation of what a certificate of analysis (COA) is, what it typically contains, who issues it, and how it fits with the other documents that come with a research material.

COA stands for certificate of analysis. A certificate of analysis is a document issued for one specific lot, or batch, of a material. It lists the tests that were performed on that lot, the methods and acceptance criteria used, and the results. For research compounds, the COA is how a lab connects the name on a label to measured data about the material in the vial.

For a field-by-field walkthrough of a peptide COA, see our guide on how to read lot documents.

What does COA stand for?

In laboratory and manufacturing use, COA, sometimes written CoA, means certificate of analysis, and the plural is COAs. The word that matters is analysis: the document reports measured results for a lot, not a general description of a product.

A certificate of analysis belongs to one lot

The defining feature of a COA is that it is lot-specific. ICH Q7, the international good manufacturing practice guide for pharmaceutical ingredients, says that authentic certificates of analysis should be issued for each batch on request^[1]. It is cited here only because it is a widely used public description of what a COA should contain. It does not mean any research material was made under it.

Under ICH Q7, a certificate should carry^[1]:

• the name of the material and, where appropriate, its grade;
• the batch number and the date of release;
• an expiry or retest date, where one applies;
• each test performed, with its acceptance limits and the numerical results obtained;
• a date and signature from authorized quality personnel.

What a peptide COA usually reports

For synthetic peptides, two results do most of the work:

• Purity by HPLC. High-performance liquid chromatography separates the components of a sample. Purity is reported as the main peak's share of the total peak area under the stated method.
• Identity by mass spectrometry (MS). MS measures molecular mass, which should match the expected mass for the stated sequence. For BPC-157, PubChem lists a molecular weight of 1419.5 g/mol and a monoisotopic mass of about 1418.70 Da^[2], so a report may show either figure depending on the instrument and how the result is expressed.

HPLC says how much of the signal is the main component; MS says whether it is the right molecule. Reviews of peptide impurities list deletion and insertion sequences, incomplete deprotection, oxidation and other by-products of synthesis and storage^[3], and impurities in commercial synthetic peptides have been shown to change downstream assay results^[4]. A single percentage without identity data and a method says little.

Purity is not content. HPLC area percent describes the share of UV-absorbing signal under one method; the powder itself can also contain counter-ions such as trifluoroacetate left from synthesis and purification^[3], as well as residual water. A certificate may report water content or net peptide content separately, and our guide on how to read lot documents covers those fields.

COA, SDS and product page: what each one answers

In the United States, OSHA's Hazard Communication Standard requires a safety data sheet for each hazardous chemical, in a fixed sixteen-section order that includes handling and storage (Section 7) and stability and reactivity (Section 10)^[5]. An SDS describes the product; a COA describes a lot. A lab typically files both. Our SDS library and COA library hold them separately for that reason.

Who issues a COA

A COA can be issued by the manufacturer's own quality-control laboratory or by a contract laboratory. "Third-party" or "independent" testing, as the terms are generally used, means the analysis was performed by a laboratory that is separate from the manufacturer and the seller. ISO/IEC 17025 is the international standard that sets general requirements for the competence of testing and calibration laboratories^[6]. When a document cites accreditation, the accreditation body and certificate number can be checked with that body.

Even regulated manufacturers do not accept certificates blindly. ICH Q7 expects at least one identity test on each incoming batch, allows a supplier's COA to replace other tests only where there is a system to evaluate suppliers, and says the reliability of certificates should be checked at regular intervals^[1].

What a COA cannot tell you

• Anything about another lot. Results belong to the batch that was tested.
• What happened after testing. Storage and handling after the test date are outside the certificate. See how to store lyophilized peptides.
• Anything about use in people. A COA records analytical results for a research material. It is not evidence of safety or suitability for human or veterinary use.

Questions to ask of any COA

• Does the lot number match the vial label and the packing slip?
• Is a test date given, and does it fit the lot's history?
• Is the laboratory that performed each test identified?
• Are the methods and acceptance criteria stated next to each result?
• Is identity shown with an observed mass, not only asserted?

Lot documents at BioLabs Research

Lot COAs are available on request and are being added to our COA library. Catalog examples include BPC-157 and TB-500. For background on the compounds themselves, see what peptides are.

Frequently asked questions

What does COA stand for?

COA stands for certificate of analysis: a document issued for one lot of a material that lists the tests performed, the methods and acceptance criteria used, and the results.

Is a COA the same as an SDS?

No. A safety data sheet describes a product's hazards, handling, storage and emergency measures and is not lot-specific. A COA reports test results for one lot.

Is a COA the same as a purity report?

No. HPLC purity is one result on a COA. Identity by mass spectrometry, the lot number, the test date, the methods and the acceptance criteria are equally important.

What does a third-party COA mean?

As the term is generally used, it means the analysis was performed by a laboratory separate from the manufacturer and the seller. The certificate should identify that laboratory so the claim can be checked.

Does a COA show that a compound is safe for people?

No. A COA records analytical results for a research material. It says nothing about safety in people, and research compounds are not for human or veterinary use.

For laboratory research use only. Not for human or veterinary use. Not a drug, food, cosmetic or dietary supplement.

References

1. ICH Harmonised Tripartite Guideline Q7, Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients, Step 4, 10 November 2000: sections 7.30–7.31, 11.4 and 11.5 (11.50, 11.52). database.ich.org/sites/default/files/Q7%20Guideline.pdf
2. National Center for Biotechnology Information. PubChem Compound Summary for CID 9941957, BPC-157. pubchem.ncbi.nlm.nih.gov/compound/9941957
3. D'Hondt M, Bracke N, Taevernier L, et al. Related impurities in peptide medicines. J Pharm Biomed Anal. 2014;101:2–30. doi:10.1016/j.jpba.2014.06.012. PMID 25044089. pubmed.ncbi.nlm.nih.gov/25044089
4. Currier JR, Galley LM, Wenschuh H, et al. Peptide impurities in commercial synthetic peptides and their implications for vaccine trial assessment. Clin Vaccine Immunol. 2008;15(2):267–276. doi:10.1128/CVI.00284-07. PMID 18077621. pubmed.ncbi.nlm.nih.gov/18077621
5. 29 CFR 1910.1200(g), Hazard Communication: safety data sheets (eCFR). www.ecfr.gov/current/title-29/section-1910.1200
6. International Organization for Standardization. ISO/IEC 17025:2017, General requirements for the competence of testing and calibration laboratories. www.iso.org/standard/66912.html