How to Verify a Certificate of Analysis

A Certificate of Analysis (COA) is the single most important document you'll encounter when evaluating a peptide product. It's supposed to tell you what's in the vial, how pure it is, and whether it's safe to use. The problem is that not all COAs are created equal — and some are outright fabricated.

In 2024, independent testing by Janoshik Analytical found that 43% of gray-market peptides failed to meet their label purity claims.^[1] Finnrick Analytics, which has tested 5,930 samples from 196 vendors, has flagged counterfeit detections and quantity discrepancies as high as 48% from the advertised amount.^[2] And in October 2025, the FDA issued a Class I recall — its most serious category — for injectable products contaminated with dangerous endotoxin levels.^[3]

This guide will teach you to read a COA critically, spot the red flags, and verify results independently. It's not complicated, but it does require knowing what to look for.

Why COAs matter

A COA is a document issued by a laboratory that certifies the results of testing performed on a specific batch of product. For peptides, it should answer three fundamental questions:

1. Is this the right molecule? (Identity testing)
2. How pure is it? (Purity analysis)
3. Is it safe to inject? (Contaminant testing — endotoxins, sterility, heavy metals)

When a COA is legitimate and thorough, it provides genuine confidence. When it's incomplete, generic, or falsified, it gives you nothing but a false sense of security.

The scale of the problem

The gray-market peptide supply chain has well-documented quality issues:^[1][2]

These are not edge cases. When nearly half of tested products fail purity claims, the COA becomes your first line of defense.^[13]

What a legitimate COA should contain

A thorough COA includes multiple sections, each serving a different purpose. Here's what to look for — and what each section actually tells you.^[6]

Peptide identity

The top of the COA should clearly state:

• Peptide name — the common name (e.g., BPC-157, semaglutide, tirzepatide)
• Amino acid sequence — the full sequence in single-letter or three-letter amino acid code
• Molecular weight — the theoretical molecular weight calculated from the sequence
• Molecular formula — the chemical formula
• Batch/lot number — a unique identifier tying this COA to a specific production run
• Manufacture date and expiration date

If any of these are missing, you're already working with incomplete information. The lot number is especially important — it's what connects this specific document to the specific vial in your hand.^[12]

HPLC purity analysis

High-Performance Liquid Chromatography (HPLC) is the standard method for measuring peptide purity.^[5] It works by separating the molecules in a sample based on how they interact with a solvent flowing through a column. The result is a chromatogram — a graph showing peaks.

How to read it:

• The x-axis is retention time (how long each molecule took to pass through the column)
• The y-axis is signal intensity (typically UV absorbance at 214–220 nm)
• The main peak represents the target peptide
• Smaller peaks represent impurities — deletion sequences, truncated fragments, oxidized variants, or synthesis byproducts

Purity is calculated as: the area under the main peak divided by the total area under all peaks, expressed as a percentage.^[5]

Important limitation: HPLC tells you how pure the sample is, but it cannot tell you what the main peak actually is. A sample could show 99% purity by HPLC while containing a completely different peptide — if that peptide happens to elute at the same retention time. That's why mass spectrometry is essential.^[6]

Mass spectrometry (MS) confirmation

Mass spectrometry measures the molecular weight of the molecules in your sample. It's the identity test — the analysis that confirms the main peak on the HPLC chromatogram is actually the peptide you think it is.^[12]

What to look for:

• Expected molecular weight — calculated from the amino acid sequence
• Observed molecular weight — the value measured by the mass spectrometer
• The match should be within +/- 1 dalton (Da) for standard peptides

For example, BPC-157 has a theoretical molecular weight of 1419.53 Da. If the MS shows 1419.5 Da, that's a confirmed identity. If it shows 1385 Da or 1502 Da, something is wrong — you may be looking at a degradation product, a deletion sequence, or an entirely different molecule.

Endotoxin testing

Endotoxins are fragments of bacterial cell walls (lipopolysaccharides) that can contaminate peptides during manufacturing. They're invisible, odorless, and heat-stable — you can't see them, smell them, or boil them away. When injected, they trigger severe inflammatory responses including fever, hypotension, organ failure, and potentially death.^[7]

The test: The Limulus Amebocyte Lysate (LAL) assay, standardized under USP ⟨85⟩, detects endotoxin contamination.^[8] Results are reported in Endotoxin Units per milliliter (EU/mL).

Acceptable limits:

Why it matters: In October 2025, the FDA classified a Class I recall — its most serious level, reserved for products that may cause death or serious harm — for NAD+ injections from GenoGenix LLC due to elevated endotoxin levels. The affected lot tested at 3,360 EU/mL — more than 6,700 times the acceptable limit. Three patients were hospitalized with hypotension and uncontrollable shaking.^[3]

Sterility testing

Sterility testing confirms the absence of viable microorganisms — bacteria, fungi, and mold. The gold standard is USP ⟨71⟩, which involves incubating samples in growth media for 14 days and checking for microbial growth.^[9]

Like endotoxin testing, sterility testing is rarely included on gray-market COAs. Compounding pharmacies operating under USP ⟨797⟩ are required to perform sterility testing on their products.^[10] Gray-market vendors labeling products "Research Use Only" are not.

Amino acid analysis (AAA)

Amino acid analysis breaks the peptide down into its individual amino acids and measures their relative proportions. This confirms the peptide composition independently of HPLC and MS. It's less commonly included on standard COAs but adds another layer of identity verification.^[12]

Peptide content / net peptide weight

This is a frequently overlooked but important measurement. A vial labeled "5 mg" may contain 5 mg of total powder — but not all of that powder is peptide. Counterions (acetate, trifluoroacetate), water, and salts make up a portion of the total weight. Peptide content, typically expressed as a percentage, tells you what fraction of the powder is actually the active peptide.

A typical peptide content value ranges from 60–85%. If a vial contains 5 mg of powder with 75% peptide content, you actually have 3.75 mg of peptide.

Red flags on a COA

Knowing what a COA should contain makes it easier to spot the ones that fall short. Here are the most common warning signs.

Suspiciously round purity numbers

Real HPLC analysis produces values like 98.4%, 97.82%, or 99.13%.^[5] If the COA reads exactly "99.00%" or "98.00%," the number was likely typed rather than measured. Analytical instruments don't produce round numbers — people do.

Missing lot or batch number

A COA without a lot number cannot be tied to a specific production run. This means there's no way to verify that the document corresponds to the actual product you received. It could be a generic template applied to every shipment.

No chromatogram or mass spectrum

If the COA claims "99% purity by HPLC" but doesn't include the chromatogram, you're being asked to trust a number without the underlying data. A reputable lab will always include the raw analytical traces.

Generic template reused across products

If the COA for BPC-157 looks identical to the one for semaglutide — same layout, same fonts, same formatting, with only the peptide name swapped — it may be a mass-produced template rather than an actual analytical report. Legitimate labs produce documents with consistent branding but product-specific data and formatting variations.

No lab identification or contact information

An authentic COA names the testing laboratory, includes its address, and often lists accreditation numbers. A document from an anonymous "certified laboratory" with no way to contact them is not verifiable.

Missing endotoxin data for injectable products

For any peptide intended for injection, the absence of endotoxin testing is a serious omission. A clean HPLC trace means nothing if the product contains dangerous levels of bacterial endotoxins.^[8]

Purity claims without method details

A legitimate COA specifies the analytical method: the HPLC column type, mobile phase, gradient conditions, and detection wavelength.^[6] Vague statements like "tested for purity" without method details are a red flag.

Dates that don't add up

Check whether the manufacture date, test date, and expiration date are logically consistent. A COA with a test date before the manufacture date, or an expiration date 5 years out for a peptide with a 2-year shelf life, suggests the document was hastily assembled.

How to verify the testing lab

A COA is only as trustworthy as the laboratory that produced it. Here's how to check.

Check for ISO 17025 accreditation

ISO/IEC 17025 is the international standard for testing and calibration laboratories.^[11] It demonstrates that the lab has been independently audited for technical competence, equipment calibration, method validation, and quality management.

How to verify:

1. Find the lab's accreditation certificate number on their COA or website
2. Go to the website of the accrediting body (common ones include A2LA, ANAB, or national accreditation bodies)
3. Search the certificate number in their database
4. Verify the lab's name, address, accreditation scope, and certificate validity dates

The scope of accreditation matters. A lab might be ISO 17025 accredited for water testing but not peptide analysis. Make sure the accreditation covers the specific test methods listed on your COA.

GMP certification

For pharmaceutical-grade products, look for current Good Manufacturing Practice (cGMP) compliance. This indicates the facility follows FDA-level manufacturing and testing standards. Compounding pharmacies should comply with USP ⟨795⟩ (non-sterile) or USP ⟨797⟩ (sterile compounding).^[10]

Verify directly with the lab

If the COA lists a lab name, call them. A legitimate lab will confirm whether they tested a specific lot number and can verify the results. Some labs, including Janoshik Analytical, maintain public databases of test results that you can cross-reference.^[1]

Fraudulent COAs sometimes list real lab names with fabricated results. Calling the lab is the definitive check.

Third-party testing options

If you want to verify a product independently — rather than relying on the vendor's own COA — you have options.

Janoshik Analytical

• Location: Prague, Czech Republic
• Specializes in: Chemical analysis of peptides, steroids, and pharmaceutical compounds
• Methods: HPLC, LC-MS/MS, NMR spectroscopy
• How to submit: Ship a sample to their lab; results are typically returned within days
• Public database: Maintains a public test results database^[1]
• Cost: Varies by test type; typically in the range of $50–150 per analysis
• Note: Janoshik is not ISO 17025 accredited, which limits its applicability in regulated clinical contexts. However, it's widely used in the research peptide community and has built a substantial track record

Finnrick Analytics

• Location: Texas, United States
• Scope: 5,930 samples tested from 196 vendors across 15 popular peptides^[2]
• Notable feature: Will test peptide samples for free — you ship, they test
• Vendor ratings: Maintains a public vendor rating database based on aggregate test results
• Most recent data: Tests uploaded through October 2025, with database updates through March 2026
• Key findings: Identified counterfeit retatrutide, quantity discrepancies up to 48%, and endotoxin contamination in gray-market products

When to seek third-party testing

• You're using a new vendor for the first time
• The vendor's COA raises any of the red flags described above
• You're working with an expensive or critical peptide where product failure has high consequences
• The product is intended for injection and the vendor COA lacks endotoxin data

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Real-world contamination data

The abstract risk of contaminated peptides becomes concrete when you look at the testing data.

Purity failures

Janoshik's 2024 testing found that lower-tier vendors routinely shipped peptides with purities of 71–91% — while their COAs claimed 99%+.^[1] That's not a rounding error. A product claiming 99% purity that actually delivers 78% purity contains more than 20% unknown impurities: deletion sequences, degradation products, synthesis byproducts, or potentially other molecules entirely.

Wrong molecule entirely

In 2025, Janoshik found that 23% of retatrutide samples submitted for testing actually contained exendin-4 analogs — a completely different peptide.^[1] The vendors' COAs for these products showed high purity and correct mass spectrometry data. The COAs were fabricated.

This is not a theoretical risk. Nearly one in four people who purchased "retatrutide" from certain vendors were injecting a different molecule.

Endotoxin contamination

Finnrick Analytics has detected endotoxin contamination in a measurable percentage of gray-market peptide samples.^[2] The FDA's October 2025 Class I recall of NAD+ injections from GenoGenix LLC — due to endotoxin levels of 3,360 EU/mL — demonstrates what happens when contaminated injectable products reach consumers.^[3] Three patients required emergency treatment.

Vendor quality collapse

Peptide Sciences, once one of the largest gray-market research peptide vendors in the United States, shut down in March 2026. Independent testing by Finnrick revealed an E rating (lowest possible) for their retatrutide product across 37 samples, along with poor scores for CJC-1295 (E rating, 4.3/10 across 10 tests).^[2] The shutdown illustrates how independent testing can expose quality problems that vendor-supplied COAs obscure.

Compounding pharmacies vs. gray market

Not all peptide sources are the same, and the COA expectations differ significantly between them.

Compounding pharmacy COAs

Pharmacies compounding peptides under USP ⟨795⟩/⟨797⟩ are required to:^[10]

• Source Active Pharmaceutical Ingredients (APIs) from FDA-registered facilities
• Test each batch against USP monograph specifications
• Perform sterility testing (USP ⟨71⟩) for sterile preparations^[9]
• Perform endotoxin testing (USP ⟨85⟩) for injectable products^[8]
• Maintain lot traceability from API source through final product
• Document beyond-use dating based on stability data

A pharmacy COA should include the pharmacy name, lot number, compound identity, potency/assay results, sterility and endotoxin results, and the responsible pharmacist's sign-off.

Gray-market COAs

Products labeled "Research Use Only" (RUO) are not required to meet pharmaceutical manufacturing or testing standards. Their COAs typically include:

• HPLC purity and mass spectrometry data (when legitimate)
• Amino acid sequence confirmation
• Batch/lot number (when provided)

They typically do not include:

• Endotoxin testing
• Sterility testing
• Potency/assay confirmation against reference standards
• USP monograph compliance
• Chain-of-custody documentation

The practical difference

A compounding pharmacy COA backed by USP standards, FDA-registered API sourcing, and mandatory sterility/endotoxin testing provides a fundamentally different level of assurance than a gray-market COA — even when the gray-market COA looks impressive on paper. The regulatory framework around pharmacy compounding exists specifically because the testing itself, without oversight, is not enough.^[4]

A practical COA checklist

Use this checklist to evaluate any COA you receive. Not every item is equally critical, but more checkmarks mean more confidence.

Identity verification

1. The COA lists the peptide name and full amino acid sequence
2. The theoretical molecular weight is stated
3. Mass spectrometry data shows an observed MW matching the theoretical MW (within +/- 1 Da)^[12]
4. A unique batch/lot number is present and matches your product label

Purity data

5. HPLC purity percentage is listed with the method specified (column, gradient, wavelength)^[5]
6. The actual HPLC chromatogram is included (not just the number)
7. The chromatogram shows a single dominant peak with minimal secondary peaks
8. Purity is above 95% for research-grade applications

Safety testing (critical for injectables)

9. Endotoxin testing results are reported (LAL assay, result in EU/mL)^[8]
10. Endotoxin level is below 0.5 EU/mL
11. Sterility testing results are reported (USP ⟨71⟩ or equivalent)^[9]

Lab credibility

12. The testing laboratory is named with full contact information
13. The lab has ISO 17025 accreditation (or equivalent) — verified in the accrediting body's database^[11]
14. The COA can be verified directly with the lab (call or check their online database)

Document integrity

15. Manufacture date, test date, and expiration date are all present and logically consistent
16. The document does not use suspiciously round purity numbers (exactly 99.00%, 98.00%)
17. The COA is specific to this product — not a generic template with the peptide name swapped in
18. A responsible analyst or quality officer is identified by name or signature

The bottom line

A COA is not a seal of approval — it's a set of claims that can be verified. The peptide market includes excellent vendors who invest in rigorous testing and documentation. It also includes vendors who photoshop purity numbers onto template PDFs. The difference between the two is not visible from a website's marketing page. It's visible in the details of the COA.

When nearly half of gray-market peptides fail independent purity testing, "trust but verify" isn't a cliche — it's a survival strategy. Learn to read the document, check the lab, and when the stakes are high, get an independent test.^[1][2]

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A scorecard for evaluating telehealth providers and compounding pharmacies — with red flags to watch for.

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News

What Happened to Peptide Sciences

The largest gray-market vendor shut down. What it means for product quality and vendor trust.

Peptide

BPC-157

The most-discussed research peptide. COA verification is especially important for gray-market compounds.

Peptide

Sermorelin

A commonly purchased peptide where COA quality directly reflects vendor reliability.

References

1. [1]

   Janoshik Analytical. “Public peptide testing database — 2024 aggregate results.” 2024. Link

   Independent analytical testing laboratory (Prague). Not ISO 17025 accredited, but widely used in the research peptide community with a substantial public track record.

2. [2]

   Finnrick Analytics. “Peptide vendor testing database — 5,930 samples from 196 vendors.” 2025. Link

   US-based independent testing service (Texas). Offers free peptide testing. Maintains public vendor rating database.

3. [3]

   U.S. Food and Drug Administration. “Class I recall: NAD+ for Injection (GenoGenix LLC) — elevated endotoxin levels.” 2025. Link

   Class I recall (most serious). Lot #GG121624-023 tested at 3,360 EU/mL. Three patients hospitalized with hypotension and uncontrollable shaking.

4. [4]

   U.S. Food and Drug Administration. “FDA's concerns with unapproved GLP-1 drugs used for weight loss.” 2025. Link

   FDA safety communication documenting adverse events from compounded semaglutide and tirzepatide, including dosing errors requiring hospitalization.

5. [5]

   Aguilar M-I. “HPLC analysis and purification of peptides.” Methods Mol Biol. 2008. 251:3–8 PubMedReview

   Foundational reference on reversed-phase HPLC methods for peptide purity analysis.

6. [6]

   Baba T, Ito T, Yoshida T, et al.. “Regulatory guidelines for the analysis of therapeutic peptides and proteins.” J Pharm Biomed Anal. 2025. DOI PubMedReview

   Comprehensive 2025 review of ICH Q2(R2), Q14, and M10 guidelines for peptide quality control.

7. [7]

   Bolden J, Smith K. “Outstanding contributions of LAL technology to pharmaceutical and medical science.” Biomedicines. 2021. 9(5):536 DOI PubMedReview

   Review of LAL assay history, methodology, and applications in pharmaceutical endotoxin testing.

8. [8]

   United States Pharmacopeia. “USP General Chapter ⟨85⟩ Bacterial Endotoxins Test.” 2025. Link

   Pharmacopeial standard defining the LAL assay and acceptable endotoxin limits for injectable products.

9. [9]

   United States Pharmacopeia. “USP General Chapter ⟨71⟩ Sterility Tests.” 2025. Link

   Pharmacopeial standard for sterility testing of pharmaceutical products. Requires 14-day incubation in two growth media.

10. [10]

    United States Pharmacopeia. “USP General Chapter ⟨797⟩ Pharmaceutical Compounding — Sterile Preparations.” 2025. Link

    Standard governing sterile compounding practices, including required testing, personnel training, and facility requirements.

11. [11]

    International Organization for Standardization. “ISO/IEC 17025:2017 — General requirements for the competence of testing and calibration laboratories.” 2017. Link

    International standard for laboratory competence. Covers personnel, equipment, method validation, and quality management.

12. [12]

    Li X, Patel N, Wesenhagen KEJ, et al.. “Reference standards to support quality of synthetic peptide therapeutics.” J Pharm Sci. 2023. 112(8):2112–2119 DOI PubMedReview

    Reviews reference standard requirements for peptide quality control, including purity assignment methodology.

13. [13]

    U.S. Food and Drug Administration. “Warning letters to compounding firms regarding GLP-1 receptor agonist products.” 2025. Link

    FDA issued 50+ warning letters to GLP-1 compounders in September 2025 for quality violations.

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