How to read a peptide COA: one real report, annotated

The document used here

The report on this page is certificate COA-2026-Q53ZYU, issued by ILS Laboratories in San Diego for BPC-157 5mg, lot BCP-2502-B. It runs to two pages, and every value quoted below is copied from it. Open the original PDF from the lot BCP-2502-B report page and read along. If you want the general meaning of a field rather than this document's entry for it, keep the field-by-field reference, how to read a certificate of analysis, open beside it.

Reports put the headline numbers first. A better reading order follows the questions: what was submitted, how it was tested, what came out, and what the laboratory says the result covers.

1. The sample block: what was submitted

Two things stand out. First, apart from the dates and the appearance check, everything in this block was supplied by the submitter, and the report says so in its footnotes (section 5). Second, the appearance entry is thin: "Good" records that nothing looked wrong but does not describe form or colour, as a stronger entry would ("white lyophilized powder"). It is a minor gap, worth writing down.

2. The summary panel: purity, content, identity, one screen

Purity: 99.59% by HPLC

Footnote 5 defines the number: purity was determined by reverse-phase HPLC with area normalization at 214 nm, and it expresses the target peptide relative to all peptide-related peaks. Reverse-phase HPLC separates the dissolved sample on a hydrophobic column, and at 214 nm the detector responds mainly to the peptide bond, so peptide-related components appear as peaks and most other things do not. The figure is the main peak's area divided by the total area of those peaks.^{[1, 2]}

Read that definition literally. It is a relative figure inside one method. The same footnote says that non-peptide process impurities, if detected, are left out of the calculation, and water, counter-ions and residual solvents were never in the denominator. The "≥ 95.0%" specification is the laboratory's own panel criterion rather than a pharmacopeial monograph, so "PASS" means the result cleared that line. The chromatogram printed on page one is the evidence behind the number; check it for shoulders and small peaks beside the main one.

Net peptide content: 5.27 mg against a 5mg label

This line answers a different question: how much of the solid in the vial is peptide. It is marked "Report only", meaning no pass or fail limit was applied. The value sits slightly above the labelled 5mg, which fits a fill set so that the peptide fraction, not the gross weight of powder, meets the label. The report does not name the method behind this line. Methods in common use include amino acid analysis, nitrogen determination and chromatographic assay against a reference standard,^[3] so if your records need the method, ask the issuing laboratory.

Identity: "Confirmed" by retention-time match

Footnote 2 says the sample was confirmed as BPC-157 by HPLC, with identification by retention-time comparison against a reference standard. The main peak eluted at the same time as an authentic reference sample run under the same conditions. That is a recognised identification approach and real evidence. It is also one-dimensional: a closely related molecule with similar chromatographic behaviour could, in principle, elute at nearly the same time. There is no observed molecular mass anywhere on this report.

Guidance written for pharmaceutical peptides recommends at least two orthogonal identification methods, naming mass, relative retention time, LC-MS, peptide mapping, amino acid analysis and NMR as suitable options, for exactly this reason.^[3] The analytical-validation guideline ICH Q2(R2) makes the general version of the same point: where one procedure cannot discriminate well enough, combine it with another.^[4] Research materials are not held to drug standards, but the yardstick is a useful one. The difference between the two kinds of evidence is covered in HPLC vs mass spectrometry.

Fentanyl screen: not detected at a 50 ng/mL cutoff

This is a targeted immunoassay for one class of contaminant. "Not Detected" means any response was below the 50 ng/mL cutoff. It is not a measurement of zero, and it says nothing about substances the assay was not built to recognise. Read any single-analyte screen as answering exactly the question it names and no other.

3. Heavy metals by ICP-MS

Five elements are listed (arsenic, cadmium, chromium, mercury and lead), each with a "not more than" limit and the result "Not Detected". Footnote 3 states that the analysis followed USP <233> methodology and that the limits are the laboratory's internal screening limits for research-use materials, not an evaluation against any monograph. Two practical notes: "Not Detected" depends on the method's reporting limit, which is not printed on the report, and the panel covers these five elements only.

4. Page two: endotoxin and sterility

Endotoxin is reported under USP <85> as "NMT 0.05 EU/mL" with the status "Reported" rather than "PASS". The laboratory's note explains why: endotoxin is a quantitative result, acceptable limits vary by product type and matrix, and no universal pass or fail threshold applies to research-use products. A concentration in EU/mL only becomes a pass or a fail when it is compared with a limit someone has defined for a specific material and purpose.^{[5, 6]}

The sterility line reads "Sterility (PCR) — No Growth — PASS". Like every other line, it describes the sample that was tested, not each vial in the lot. The method label names PCR, a molecular technique that detects microbial DNA, while "No Growth" is the vocabulary of culture-based testing. If your acceptance criteria depend on which kind of method was used, ask the laboratory to confirm it in writing.

5. The footnotes: what the laboratory stands behind

Footnote 6 is the most important sentence on the report for anyone matching a vial to a document. It says that sample identifications, product names, lot numbers and labelled content are "provided by the submitting party and have not been independently verified". The laboratory tested what it was sent and reports on that sample. The link between the sample and lot BCP-2502-B rests with the submitter.

That is normal practice, not a weakness peculiar to this report. ISO/IEC 17025 requires test reports to state that results relate only to the items tested, and European Accreditation's guidance says the statement exists so that results are not read as lot approval or product certification.^{[7, 8]} How to judge the sample-to-lot link yourself is the subject of lot traceability: how to match a vial to its lab report.

The footer reads "Testing performed under ISO/IEC 17025 quality management system." The wording varies between versions of this laboratory's reports: some read "ISO/IEC 17025 Accredited", and a later version adds that accreditation covers the activities listed in the laboratory's published PJLA scope and that peptide testing is performed for research use. Accreditation is granted for a defined list of methods, so the useful question is whether a given method appears on that list.^[9]

6. Signature and verification

The report is signed by the laboratory director, dated 8/25/2026, and carries the certificate number, an access code and the address of the laboratory's verification portal. The verification page for this certificate shows the client, product, lot number, appearance, test type, date received and analysis date as the laboratory holds them. Compare each against the PDF. Because that page is hosted by the laboratory, not the seller, the check is independent.

What this report does not tell you

• An observed molecular mass, or any mass-spectrometric identity result.
• Water content.
• Which counter-ion is present (acetate or trifluoroacetate) or how much.
• Residual solvents.
• A list of the individual impurities that make up the 0.41% outside the main peak.
• Anything about other lots or strengths, including BPC-157 10mg, which has no separately published report.

None of these gaps is unusual for a research-material report. Writing them down is the point: a reader who knows what a document covers will not lean on it for something it never measured.

The same template on other published lots

Arctic Lab Supply's other current reports from this laboratory use the same template, though the panel varies by lot: the GLOW and Melanotan reports, for example, have no heavy-metals or sterility section. The four lots below carry the same full panel as the example, and all four samples were received by the laboratory on 07/28/2026.

On all four, identity is by HPLC retention-time match. The RT-2502-B report adds a note that purity values are capped at 99.9% to reflect the instrument's limit of detection, and that trace impurities below that threshold may be present. A result printed at the cap means "at least this pure under this method", not an exact figure. The full list of current reports, with PDFs and verification links, is in the batch COA library.

Frequently asked questions

What is the most important line on a peptide COA?

The lot number, because it decides whether the rest of the document applies to the vial in front of you. After that, read the identity method, then the purity figure together with the method behind it.

Does “Identity: Confirmed” mean the molecular mass was measured?

Not necessarily. On the report used here, identity was confirmed by matching the HPLC retention time against a reference standard, and no molecular mass is reported. The method line or the footnotes say which technique was used.

Why is the net peptide content higher than the label?

The vial is filled so that the peptide fraction, not the gross weight of powder, meets the labelled amount. On lot BCP-2502-B the measured peptide content is 5.27 mg for a 5mg label.

What does “Report only” mean on a certificate of analysis?

The laboratory measured and reported the value without applying a pass or fail limit. It is information, not a judgement.

If a report says PASS, is the whole lot approved?

No. PASS means the tested sample met the criterion the laboratory applied to that line. Reports issued under ISO/IEC 17025 state that results relate only to the items tested.

Sources

1. United States Pharmacopeia, General Chapter <621> Chromatography. https://doi.usp.org/USPNF/USPNF_M99380_70101_01.html
2. Mant CT, Chen Y, Yan Z, et al. HPLC analysis and purification of peptides. Methods in Molecular Biology 386:3–55 (2007). https://doi.org/10.1007/978-1-59745-430-8_1
3. European Medicines Agency. Guideline on the Development and Manufacture of Synthetic Peptides, EMA/CHMP/CVMP/QWP/367182/2025, in effect from 1 June 2026 (identification and specification sections). https://www.ema.europa.eu/en/development-manufacture-synthetic-peptides-scientific-guideline
4. ICH Q2(R2) Validation of Analytical Procedures, FDA guidance edition (section 3.1, specificity/selectivity). https://www.fda.gov/regulatory-information/search-fda-guidance-documents/q2r2-validation-analytical-procedures
5. U.S. FDA. Guidance for Industry: Pyrogen and Endotoxins Testing — Questions and Answers. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-pyrogen-and-endotoxins-testing-questions-and-answers
6. United States Pharmacopeia, General Chapter <1085> Guidelines on the Endotoxins Test. https://doi.usp.org/USPNF/USPNF_M2245_03_01.html
7. ISO/IEC 17025:2017, General requirements for the competence of testing and calibration laboratories. https://www.iso.org/standard/66912.html
8. European Accreditation, FAQ 42.1 on ISO/IEC 17025:2017 clause 7.8.2.1 l) (results relate only to the items tested). https://european-accreditation.org/sp_accordion_faqs/42-1-question-on-reporting-iso-iec-170252017-cl-7-8-2-1-l/
9. Perry Johnson Laboratory Accreditation (PJLA), accredited laboratory search (for checking a laboratory's published scope). https://www.pjlabs.com/search-accredited-labs

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