ISO 17025 Accreditation and What a Peptide Certificate of Analysis Actually Proves

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"ISO 17025 accredited" appears on a growing share of peptide product pages. The phrase functions, in many of these contexts, as a quality signal: the product has been tested, the testing is rigorous, the buyer should be reassured. The phrase is also routinely misunderstood. ISO 17025 is an international standard, but it does not accredit products. It accredits laboratories. A peptide product associated with an ISO 17025 accredited laboratory has had its testing performed under a recognized quality system. Everything else about the product, including its sourcing, its manufacturing controls, and its connection to the testing it claims, requires separate documentation.

This article describes what ISO 17025 actually accredits, what the standard testing methods on a peptide certificate of analysis (COA) measure, what those measurements demonstrate and do not demonstrate, and how a buyer can verify the documentation chain back to the public accreditation databases that the accreditation bodies maintain.

What ISO 17025 is

ISO/IEC 17025:2017, "General requirements for the competence of testing and calibration laboratories," is the international standard for laboratory competence. The standard is jointly maintained by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC).1

A laboratory accredited under ISO 17025 has demonstrated, to an accreditation body, that it operates a documented quality management system, employs competent personnel, uses validated analytical methods, maintains traceable measurement standards, and produces results with documented uncertainty. The accreditation covers specific testing methods, called the laboratory's "scope of accreditation," not the laboratory's testing in general. A laboratory accredited for HPLC analysis is accredited for that method; another method requires separate accreditation.

The accreditation is a competence claim about the testing process. It is not a claim about the sample tested, the source of the sample, or any other aspect of the product the sample is drawn from.

Accreditation bodies

Accreditation under ISO 17025 is performed by accreditation bodies, organizations that are themselves recognized through an international peer review process maintained by the International Laboratory Accreditation Cooperation (ILAC) and regional partners. In the United States, the two largest accreditation bodies for testing laboratories are the American Association for Laboratory Accreditation (A2LA) and the ANSI National Accreditation Board (ANAB).2

Both bodies maintain searchable public databases of accredited laboratories, including the laboratory's scope of accreditation and the current status of the accreditation. A buyer who wants to verify that a laboratory cited on a peptide COA is actually ISO 17025 accredited can search the appropriate database directly and confirm the accreditation, the scope, and the expiration date.3

This is the single most consequential verification step a buyer can take. A COA from a laboratory that is not in the accreditation body's database, or whose accreditation has lapsed, or whose scope does not include the testing methods on the COA, is a COA with diminished evidentiary weight. The accreditation claim is verifiable in public databases. A claim that does not verify is a claim that should be treated as unverified.

The standard tests on a peptide COA

Peptide certificates of analysis typically report results from three to five analytical tests. Each test addresses a different question about the sample and is performed using established methods.

High-performance liquid chromatography (HPLC) for purity. HPLC separates the components of a sample by passing it through a chromatography column and detecting each component as it elutes. For peptide purity testing, the method identifies the intended peptide and any related impurities (synthesis byproducts, truncated sequences, related substances). The result is reported as a percentage, the area-under-curve of the intended peptide peak divided by the total area-under-curve of all detected peaks. Pharmaceutical-grade peptides typically report 98 percent or higher purity by HPLC.4

HPLC purity tells the buyer what percentage of the detected material is the intended peptide. It does not tell the buyer that the intended peptide is the labeled peptide. That question requires a separate test.

Mass spectrometry for identity. Mass spectrometry measures the molecular mass of compounds in a sample by ionizing the molecules and detecting them in an electric or magnetic field. For peptide identity testing, the method measures the actual mass of the synthesized peptide and compares it to the theoretical mass calculated from the labeled amino acid sequence. A correct match within the instrument's mass accuracy confirms that the peptide has the labeled molecular formula. A mismatch indicates that the sample is not the labeled peptide, that it has the wrong sequence, or that it contains an unexpected modification.5

Mass spectrometry establishes molecular identity. It does not by itself confirm the exact amino acid sequence; two different peptides with the same amino acid composition but different sequences will have the same mass. Sequence confirmation requires either tandem mass spectrometry (MS/MS) or Edman sequencing, both of which are reported on more thorough COAs.

Limulus Amebocyte Lysate (LAL) assay for endotoxin. The LAL assay detects bacterial endotoxins in injectable preparations by exploiting the clotting reaction of horseshoe crab blood cell lysate when exposed to lipopolysaccharide from gram-negative bacteria. The United States Pharmacopeia specifies endotoxin limits for parenteral preparations under USP General Chapter 85.6 Pharmaceutical-grade injectable peptides are tested against those limits and report endotoxin units per milligram on the COA.

LAL testing confirms that the peptide preparation does not contain enough endotoxin to produce acute pyrogenic reactions in injection. It does not confirm sterility (the absence of viable microorganisms), which is a separate test under USP General Chapter 71.

Sterility testing. For lyophilized injectables intended for human or animal use, sterility testing under USP General Chapter 71 confirms that the finished product does not contain viable microorganisms. The test is performed by culturing samples in defined growth media and observing for microbial growth over a defined period.7

Water content (Karl Fischer titration). The water content of a lyophilized peptide is relevant to stability and to the accuracy of dose calculations. Karl Fischer titration measures water content directly. Pharmaceutical-grade lyophilized peptides typically report water content as a percentage on the COA.

Batch-specific versus generic certificates

A COA is either batch-specific or generic. The distinction is consequential.

A batch-specific COA reports the test results for a specific manufacturing batch (identified by a batch or lot number) and links those results to the customer's product by matching the batch number on the COA to the batch number on the vial. The test results describe the product the customer received.

A generic COA reports test results for a representative or typical batch and does not link to any specific customer product. A vendor that publishes a generic COA is providing reference data that some batches of their product have met. A customer's actual vial may or may not match those reference data.

The batch-specific COA is the form that has evidentiary value for the customer's actual product. The generic COA has reference value but does not document the specific material the customer is purchasing. A buyer who cannot trace a COA's batch number to the lot number on a vial has not actually verified the product they received.

What the documentation chain looks like, end to end

A peptide product with fully documented quality has a verifiable chain that runs as follows.

The active pharmaceutical ingredient is manufactured at a named facility, registered with the FDA (for products entering the US market) or with an equivalent foreign regulatory authority. The manufacturing facility is identifiable by name and address, and its registration can be verified in the FDA's DECRS database.8

The manufacturing batch produces a lot of finished material identified by a batch or lot number. A sample of the batch is sent to a testing laboratory for analytical confirmation.

The testing laboratory performs the specified tests under validated methods. The laboratory is ISO 17025 accredited for those methods, with accreditation verifiable in the accreditation body's database. The test results are issued on a COA that identifies the laboratory, the methods used, the batch tested, and the results for each test.

The finished product is packaged with the batch or lot number on the vial label, allowing the customer to match the physical product to the COA.

A product with this documentation chain is independently verifiable. A buyer can confirm the manufacturing facility's FDA registration, confirm the laboratory's ISO 17025 accreditation, confirm the testing scope, and match the batch number on the vial to the batch on the COA. The verification can be done without trusting any unverified vendor claim.

What ISO 17025 accreditation does not do

The accreditation is competence certification for testing. It does not address several other quality dimensions that matter for a peptide product.

It does not certify the manufacturing facility. A peptide manufactured at an unaccredited and unregistered facility can be tested by an ISO 17025 accredited laboratory and produce a valid COA. The COA documents what the testing found in the sample submitted. It does not document the conditions under which the peptide was synthesized.

It does not address chain of custody. The accreditation does not verify that the sample tested was actually drawn from the batch represented or that the COA's results correspond to the material the customer receives. Chain of custody is a documentation question between the manufacturer and the laboratory, separate from the laboratory's accreditation.

It does not establish suitability for any particular use. The accreditation confirms that the testing meets a quality standard. It does not confirm that the peptide tested is appropriate for any specific application. That determination requires additional regulatory framework that ISO 17025 does not provide.

The verification routine

A buyer evaluating a peptide product can perform a complete verification routine using public resources. The routine includes the following steps.

Locate the COA. The COA should be batch-specific, with a batch or lot number that can be matched to the product vial.

Identify the testing laboratory on the COA. Search the A2LA or ANAB accreditation database for the laboratory's name. Confirm that the laboratory is currently accredited, that the accreditation has not expired, and that the scope of accreditation includes the methods listed on the COA.

Identify the manufacturing facility, if listed. For US-distributed products, search the FDA DECRS database to confirm the facility's drug establishment registration.

Compare the batch number on the COA to the batch number on the product vial. The two should match.

For each test result reported, confirm that the result meets a defined specification. HPLC purity should specify a minimum (98 percent or higher for pharmaceutical-grade preparations). Mass spectrometry should report a mass match within instrument tolerance. Endotoxin testing should report a result within USP limits.

A product that passes this verification is documented at a level the prescription drug market would recognize as appropriate. A product that fails one or more of these checks has a documentation gap that the buyer is taking on faith.

What this means for the market

The peptide market has historically operated under a documentation standard far below what the prescription drug market requires. The shift currently underway, driven by the FDA enforcement activity discussed elsewhere in this collection and by the broader regulatory developments around peptide compounding, is moving the standard upward. The buyers who can verify their products against the documentation chain described above are the buyers who are operating in the more mature segment of the market.

ISO 17025 accreditation, batch-specific COAs, and FDA-registered manufacturing facilities are not exotic features. They are the baseline that drug manufacturing has used for decades. They are also the features that distinguish a documented peptide product from an undocumented one. The verification work described in this article is the verification work a careful buyer should do as a matter of routine.

Footnotes

1. International Organization for Standardization, ISO/IEC 17025:2017. https://www.iso.org/standard/66912.html
   
2. International Laboratory Accreditation Cooperation (ILAC). https://ilac.org/. ILAC maintains the international peer review process that recognizes accreditation bodies.
3. A2LA accredited laboratory directory. https://www.a2la.org/directory-search. ANAB accredited laboratory directory. https://search.anab.org/
   
4. United States Pharmacopeia, General Chapter <621> Chromatography. Standard methods for chromatographic analysis including HPLC. [verify current chapter reference]
5. Aebersold R, Mann M. "Mass spectrometry-based proteomics." Nature. 2003;422(6928):198-207. Foundational reference for mass spectrometry-based peptide identification. https://pubmed.ncbi.nlm.nih.gov/12634793/
   
6. United States Pharmacopeia, General Chapter <85> Bacterial Endotoxins Test. Standard reference for the LAL assay. [verify current chapter reference]
7. United States Pharmacopeia, General Chapter <71> Sterility Tests. Standard reference for sterility testing of compendial articles. [verify current chapter reference]
8. FDA Drug Establishments Current Registration Site (DECRS). https://www.accessdata.fda.gov/scripts/cder/drls/default.cfm
   
9. Frier Levitt, "Regulatory Status of Peptide Compounding in 2025," January 2026. https://www.frierlevitt.com/articles/regulatory-status-of-peptide-compounding-in-2025/
   
10. LegitScript, "Understanding Peptides: A Q&A Guide for Payment Processors," October 2025. https://www.legitscript.com/wp-content/uploads/2025/10/Peptides-for-Payment-Processors-Guide.pdf