Red Flags in Peptide Sourcing: Spotting Fake CoAs and Stock Purity Graphics

 

A Certificate of Analysis (CoA) is supposed to be your primary assurance of peptide quality. Unfortunately, the document itself has become a tool of deception. Spotting red flags has become an essential skill for any researcher or buyer due to fabricated reports, stolen lab data, and "stock purity graphics" that have no connection to the product received.

The Single Most Important Question: Who Actually Ran the Test?

The most crucial piece of information on any CoA is the name of the lab that performed the analysis. There is a fundamental difference between a supplier's internal quality claim and an independent third-party report .

In-house testing means the vendor tested their own product in theirreport.ility. While this is better than no testing, it comes with an inherent conflict of interest—the vendor has a financial incentive to report favourable results.

Third-party testing from an independent, accredited lab is the gold standard. Look for named, verifiable labs like Janoshik Analytical. If the CoA does not clearly name an independent lab, treat every number as a claim rather than a verified result.

The Batch Number Trap: The Most Common Oversight

A CoA certifies a specific production lot. Purity varies between batches, so a certificate for one batch means nothing for another.

Two critical checks:

• Does the CoA have a batch number? Without one, the document cannot be traced to any specific product.

• Does it match your vial? If the batch number on the CoA does not match the one on your product label, the testing does not apply to what you received.

Some vendors reuse documentation from previous batches or apply batch numbers retroactively. This practice turns the CoA into decoration rather than documentation.

Red Flag 1: Purity Without the Chromatogram

A purity claim of "99.2%" is easy to type. Without the underlying HPLC chromatogram showing the peak data that produced that figure, the number is meaningless.

A legitimate HPLC result includes:

• A chromatogram image showing the peak profile

• The main compound peak is clearly dominant

• Run conditions (column type, mobile phase, gradient, detection wavelength)

• Peak area integration values that add up to the reported purity 

If you see only a purity percentage with no chromatogram, ask the supplier for the raw data. Refusal or inability to provide it clearly signals the figure lacks grounding in actual testing.

Red Flag 2: Missing Mass Spectrometry Identity Confirmation

HPLC tells you how pure the sample is. Mass spectrometry (MS) tells you what the compound actually is. A 99% pure sample could be 99% pure wrong compound.

A complete CoA includes both the theoretical molecular mass of the compound and the observed mass from LC-MS analysis. These should match within the instrument's tolerance (typically within ±0.5 Da).

A CoA without MS data has a critical gap in the identity verification chain. For complex peptides like tirzepatide or retatrutide, this is especially important because even small synthesis errors can produce a peptide of nearly identical HPLC retention time but different biological properties.

Red Flag 3: Suspiciously Round or Universal Purity Figures

If every product on a supplier's site carries the same purity to two decimal places (e.g., 99.23%), that is a template, not a set of measurements. Real batches vary.

Similarly, if a supplier assures you "all products have purity over 99%" without providing per-batch documentation, that describes a catalogue, not your vial. It is a marketing statement, not a quality guarantee.

Red Flag 4: COA Date Anomalies

A simple but revealing check: Does the COA testing date make sense?

• If the testing date predates the supplier's domain registration, company founding, or first public appearance, the document cannot be authentic .

• A compound tested in January should not appear in an order placed in December of the previous year .

Date anomalies are a reliable signal that the document was not generated for the product you are receiving .

Red Flag 5: Stolen or Fabricated Lab Reports

This is one of the most alarming trends: vendors stealing legitimate CoAs from other companies and passing them off as their own .

In one documented case, a WhatsApp seller provided approximately 40 CoAs that a testing lab confirmed had been doctored. Every CoA they provided had been stolen from another supplier .

A vendor intelligence report documented another case where a supplier's displayed CoA from one testing lab actually verified to a different vendor entirely—proving the documentation had been misappropriated .

How to Verify CoA Authenticity

• Request a verification URL. Many labs allow you to verify the original CoA on their website. A vendor should provide a URL so you can see the original document directly from the testing lab's website—not just a shareable PDF, which can be easily modified .

• Check the lab name against the vendor. If the lab name matches the vendor's company name, it is in-house testing, not independent verification .

• Look for inconsistent lab usage. Some vendors bounce between multiple testing labs (AFI, Kovera, Freedom, ILS) without clear explanation. While this can sometimes reflect legitimate efforts to build a more complete testing program, it also raises questions about COA shopping—seeking out labs that produce favorable results .

Summary: A 30-Second Checklist

Before trusting any CoA :

• An independent lab is named—not just the supplier

• The batch number on the report matches your vial

• Both HPLC (purity) and MS (identity) are present

• The chromatogram is included, not just a percentage

• The testing date makes sense for the product

• The purity figure is not suspiciously round or universal

• The supplier can provide a verification URL from the testing lab