How to Identify Counterfeit or Degraded Peptides

A vial arrives in the mail. The label says BPC-157 or semaglutide. The certificate of analysis claims 99% purity. But here is the uncomfortable truth: without verification, you have no idea what is actually in that vial. The research peptide market operates largely outside FDA oversight, and that gap between what a label promises and what a product delivers can be enormous. In June 2025, federal agents raided one of the largest online peptide vendors — Amino Asylum — shutting it down for alleged product spiking, unapproved marketing, and selling mislabeled compounds. That was not an isolated case. It was a symptom of a market where counterfeiting, contamination, and degradation are widespread problems.

This guide walks you through how to spot fake or degraded peptides before they ever reach your body — from visual inspection to analytical testing to the vendor red flags that should send you running.

Table of Contents

• Why Counterfeit Peptides Are So Common
• Visual Inspection: What You Can See
• Understanding Certificates of Analysis
• How to Spot a Fake COA
• Analytical Testing Methods Explained
• Third-Party Testing: Your Best Defense
• Common Counterfeiting Tactics
• Vendor Red Flags
• Signs of a Legitimate Vendor
• Purity vs. Net Peptide Content: A Critical Distinction
• The Bottom Line
• References

Why Counterfeit Peptides Are So Common

The peptide market sits in a regulatory no-man's land. Research-grade peptides are not regulated as drugs, supplements, or food. As LegitScript, a verification company that monitors online pharmacies, has documented, these compounds exist as "new substances without a regulatory home."

That creates an environment where quality control is entirely voluntary. Paul Knoepfler, a cellular biologist at UC Davis, put it bluntly in a 2025 CNN report: "Research-grade peptides are going to have junk in them. They're going to have chemicals used in the purification process and fragments of peptides that you don't want."

The economics are straightforward. Synthesizing a high-purity peptide with proper quality controls costs significantly more than cutting corners. On platforms like TikTok, companies offer to ship peptide vials from overseas for as little as $5 each. At that price point, rigorous manufacturing and testing are not part of the equation.

Visual Inspection: What You Can See

Visual inspection is your first line of defense, but it comes with an important caveat: passing a visual check does not mean a peptide is legitimate. It only means nothing has gone obviously wrong. Failing a visual check, however, is a definitive signal to discard the product.

Lyophilized (Freeze-Dried) Powder

A properly manufactured lyophilized peptide should appear as a dry, white to off-white powder or cake at the bottom of the vial. Watch for these warning signs:

• Discoloration. Yellowing or browning indicates chemical degradation, often from oxidation or moisture exposure.
• Clumping or stickiness. This suggests moisture has entered the vial. Lyophilized peptides should be loose and dry.
• No visible powder. If the vial appears empty or has only a thin residue, it may have been improperly filled or the powder degraded completely.
• Inconsistent appearance across vials. If you purchase multiple vials from the same batch and they look different from each other, that points to inconsistent manufacturing.

Reconstituted Solutions

After you reconstitute a peptide, it should dissolve into a clear, colorless to very slightly yellow solution. The exceptions are peptides containing copper, like GHK-Cu, which naturally have a blue tint.

Red flags in reconstituted peptides include:

Warning Sign	What It Means
Cloudiness or haziness	Peptide aggregation — solution should not be used
Visible particles or floaters	Contamination or precipitation — discard the vial
Significant color change	Chemical degradation has occurred
Difficulty dissolving	Possible degradation, wrong peptide, or moisture damage to the lyophilized powder
Unusual or foul smell	Bacterial contamination likely — discard immediately

One critical point: even a perfectly clear solution can contain the wrong peptide, a contaminated peptide, or a degraded peptide that has lost its biological activity. Visual inspection catches gross problems. It cannot confirm identity, purity, or potency.

Understanding Certificates of Analysis

A Certificate of Analysis (COA) is a document from a laboratory that reports the results of quality testing on a specific batch of peptide. A legitimate COA should include:

• Product identification — peptide name, molecular formula, molecular weight, amino acid sequence
• Batch/lot number — unique identifier that matches the product label
• HPLC purity data — including a chromatogram (the graph showing the analysis), column type, mobile phase, detection method, and conditions
• Mass spectrometry (MS) data — confirming the molecular identity of the peptide
• Date of analysis
• Storage recommendations
• Laboratory name and contact information

A COA with only an HPLC purity number and no mass spectrometry data is incomplete. HPLC tells you how pure a sample is; mass spectrometry tells you what it actually is. A peptide missing one amino acid can look 99% pure on HPLC while being the wrong compound entirely.

How to Spot a Fake COA

Testing labs that work with peptide vendors have reported catching forged COAs that use stolen logos, fabricated signatures, and headers from legitimate laboratories. Here is what to look for:

Red Flags in COAs

Unrealistic purity claims. A purity reading of 100.0% is essentially impossible in analytical chemistry. Even 99.99% should raise eyebrows. Legitimate results show realistic numbers — 98.7%, 99.2% — with appropriate decimal precision.

Mismatched lot numbers. If the lot number on your vial does not match the lot number on the COA, that document does not verify your specific product. Some vendors recycle a single COA across multiple batches.

Vague method descriptions. "Tested by HPLC" tells you almost nothing. A real COA specifies the column type (e.g., C18 reverse-phase), mobile phase composition, flow rate, detector wavelength (typically 210-220 nm for UV), and run conditions.

No chromatogram. The HPLC chromatogram — the actual graph output from the instrument — is a key piece of evidence. A COA that reports a purity percentage without the chromatogram is like a medical test with results but no lab report.

Generic or templated formatting. If every COA from a vendor looks identical except for the peptide name and purity number, they may be generating documents from a template rather than actual test results.

How to Verify a COA

1. Check for online verification. Labs like Janoshik Analytical include QR codes and unique task IDs on their reports. You can enter these on their website to confirm the report is authentic and unaltered.
2. Contact the testing lab directly. Email the laboratory listed on the COA with the report ID and ask them to confirm they tested that batch.
3. Cross-reference the lab. Search for the testing laboratory independently. Does it have a website? A physical address? Published contact information? If the "lab" on a COA does not appear to exist, the COA is fabricated.

Analytical Testing Methods Explained

Understanding the testing methods helps you evaluate COAs and decide whether to invest in independent testing.

HPLC (High-Performance Liquid Chromatography)

HPLC is the gold standard for measuring peptide purity. The technique works by separating a peptide mixture into its individual components. The result is a chromatogram where the main peak represents the target peptide, and smaller peaks represent impurities.

Purity is calculated as the area of the main peak divided by the total area of all peaks, expressed as a percentage. A research-grade peptide typically shows purity above 95%. Pharmaceutical-grade compounds aim for 98-99% or higher.

What HPLC cannot do: confirm that the main peak is actually the peptide you ordered. A completely different peptide of similar size and hydrophobicity could produce a clean, high-purity HPLC result.

Mass Spectrometry (MS)

Mass spectrometry answers the fundamental question: is this actually the peptide I think it is? The technique measures the molecular weight of the compound with extreme precision. If the measured mass matches the expected mass for a given peptide sequence, you have confirmation of identity.

Two main MS approaches are used in peptide analysis:

• MALDI-TOF produces single-charge ions, making the spectra straightforward to interpret. It is fast and tolerant of sample impurities, which makes it practical for routine identity checks.
• ESI-MS produces multiply-charged ions and offers higher sensitivity. It works well for larger peptides and can be coupled directly to HPLC systems for combined purity-and-identity analysis.

For reference, when testing leuprolide (a well-characterized FDA-approved peptide), the theoretical mass of 1209.6533 Da matched an experimental measurement of 1209.6515 Da — confirming identity with precision to the fourth decimal place.

Additional Testing Methods

Method	What It Measures	When It Matters
Amino acid analysis	Actual amino acid composition and net peptide content	Confirms composition and quantifies how much of the vial is actually peptide vs. salts and water
Endotoxin testing (LAL)	Bacterial endotoxin contamination	Important for any injectable peptide
Sterility testing	Microbial contamination	Confirms the vial is free from bacteria and fungi
Heavy metals testing	Lead, mercury, arsenic, cadmium levels	Important for peptides sourced from manufacturers with unknown quality controls

Third-Party Testing: Your Best Defense

If you want definitive answers about what is in a vial, independent third-party testing is the only reliable path. Several laboratories offer peptide verification services:

Janoshik Analytical has become widely used in the research community. They provide HPLC purity analysis and mass spectrometry identity confirmation, with online-verifiable reports. However, critics note that Janoshik does not hold ISO/IEC 17025 accreditation, which is the international standard for testing laboratory competence.

Chromate offers analytical testing with QR-code-verifiable COAs. They are frequently referenced alongside Janoshik as a trusted third-party verification resource.

MZ Biolabs provides HPLC and mass spectrometry analysis with a verification platform for confirming report authenticity.

Testing Costs

Test Type	Approximate Cost
HPLC purity analysis	$100-200 per sample
HPLC + mass spectrometry	$200-350 per sample
Endotoxin testing	$75-150 per sample
Heavy metals panel	$100-200 per sample

These costs may seem high relative to the price of a single vial. But consider what you are comparing against: injecting an unverified substance into your body. For anyone using peptides therapeutically — especially at significant ongoing cost — periodic independent testing is a rational investment.

Common Counterfeiting Tactics

Knowing the playbook helps you spot the scheme. Here are the most common counterfeiting and fraud tactics in the peptide market:

Underdosed vials. The vial contains the correct peptide but at a lower quantity than labeled. A vial labeled as 5 mg may contain 3 mg or less. This is one of the hardest forms of fraud to detect without potency testing because the peptide is technically present and will produce some effect.

Substituted peptides. A cheaper peptide is substituted for a more expensive one. This is particularly common with peptides that share similar physical characteristics after reconstitution. Mass spectrometry is the only reliable way to catch this.

Contaminated products. The peptide is present but contaminated with synthesis byproducts, bacterial endotoxins, heavy metals, or other peptide fragments. HPLC catches peptide-related impurities; endotoxin and heavy metals testing catch the rest.

Cloned vendor websites. Some operations clone well-known peptide vendor websites and change only the payment portal. Always verify the domain name carefully before making a purchase, and bookmark verified vendors rather than following links from search results or social media.

Fabricated COAs. As discussed above, some vendors create entirely fictitious testing documents, sometimes stealing logos and formatting from legitimate laboratories.

Relabeled research chemicals. Products manufactured for non-human research use, with lower purity standards and no sterility controls, are repackaged with labels suggesting clinical or pharmaceutical quality.

Vendor Red Flags

These are the warning signs that should make you look elsewhere:

"Not for human consumption" disclaimers prominently displayed. LegitScript has found that merchants who prominently state their products are not intended for human consumption are, counterintuitively, more likely to be selling products intended for exactly that purpose. The disclaimer is a legal fig leaf, not a quality signal.

No COAs available or COAs that cannot be verified. If a vendor cannot or will not provide batch-specific testing documentation, there is no basis for trusting the product.

Prices dramatically below market rate. Peptide synthesis with proper quality controls has a floor cost. Vials offered at $5-10 from overseas suppliers are priced below what legitimate manufacturing costs.

No batch traceability. Legitimate suppliers assign unique batch numbers to every product. Generic or unmarked vials indicate no accountability system.

No storage or handling guidance. A vendor that does not mention lyophilized storage requirements, temperature stability, or light protection either does not understand their product or does not care about its integrity by the time it reaches you.

Flood of perfect reviews with no negative feedback. Fake vendors often generate artificial 5-star reviews while suppressing public feedback platforms. Look for reviews on independent forums, not just the vendor's own website.

Social media-driven sales with no verifiable business presence. A company that exists only as an Instagram account or TikTok page, with no physical address, published phone number, or business registration, is not operating with accountability.

Signs of a Legitimate Vendor

Legitimate peptide suppliers typically demonstrate these characteristics:

• Third-party COAs for every batch, with verifiable testing data including both HPLC purity and mass spectrometry identity confirmation
• Clear batch/lot numbering that traces each product to its specific manufacturing run
• Transparent sourcing information about where active pharmaceutical ingredients originate
• Published storage and handling instructions
• Responsive customer service with identifiable contact information
• Proper shipping practices, including cold-chain shipping for temperature-sensitive products
• PCCA membership or equivalent industry affiliations (for compounding pharmacies)

For compounding pharmacies specifically, look for PCAB accreditation, state licensure, and compliance with USP <797> sterile compounding standards.

Purity vs. Net Peptide Content: A Critical Distinction

This is one of the most commonly misunderstood concepts in peptide quality, and vendors who want to obscure product quality exploit that misunderstanding.

Purity measures the target peptide relative to other peptide-related impurities. If a sample is 99% pure, it means 99% of the peptide-related material is the correct compound, and 1% consists of synthesis byproducts, truncated sequences, or other peptide impurities.

Net peptide content measures the target peptide relative to everything in the vial — including water, salts (particularly TFA, or trifluoroacetic acid, a common counter-ion from synthesis), and non-peptide components.

Here is the critical point: a peptide can be 99% pure by HPLC and still have a net peptide content of only 70-80%. That means in a vial labeled as containing 5 mg of peptide, only 3.5-4 mg may actually be active peptide. The rest is water, salts, and counter-ions.

This is not necessarily fraud — it is standard chemistry. But a vendor who advertises "99% purity" without disclosing net peptide content is giving you an incomplete picture. Amino acid analysis is the test that determines actual peptide content.

The Bottom Line

Identifying counterfeit or degraded peptides requires a layered approach. Visual inspection catches obvious problems. COA review filters out vendors who cannot or will not document quality. Analytical testing provides definitive answers.

No single check is sufficient on its own. A clean-looking vial with a professional label can contain the wrong compound. A COA with impressive numbers can be fabricated. Even a legitimate third-party test only verifies that specific vial — not every vial from the same vendor.

The most practical strategy is to combine multiple verification steps: choose vendors with documented quality systems, review batch-specific COAs critically, learn to read a peptide COA properly, and invest in independent third-party testing when the stakes justify it. If you are working with a prescribing clinician, ask where the peptide is sourced, whether the pharmacy has appropriate accreditation, and whether batch testing documentation is available.

For anyone considering peptide therapy, understanding potential side effects and working with a qualified healthcare provider remain the most important safety measures — but verifying that you have the right product in the first place is the foundation everything else builds on.

References

1. SURPASS-2 Trial. "Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes." New England Journal of Medicine, 2021. https://www.nejm.org/doi/full/10.1056/NEJMoa2107519

2. Vanguard Laboratory. "The Ultimate Guide to HPLC Testing for Peptides." 2025. https://vanguardlaboratory.com/2025/12/08/the-ultimate-guide-to-hplc-testing-for-peptides/

3. PMC. "Reference Standards to Support Quality of Synthetic Peptide Therapeutics." 2023. https://pmc.ncbi.nlm.nih.gov/articles/PMC10338602/

4. LegitScript. "The Growing Risk of Peptides: What Online Platforms and Payment Processors Need to Know." 2025. https://www.legitscript.com/high-risk-and-problematic-products/the-growing-risk-of-peptides-what-online-platforms-and-payment-processors-need-to-know/

5. CNN. "The Trend of Unproven Peptides Is Spreading Through Influencers and RFK Jr. Allies." November 2025. https://www.cnn.com/2025/11/15/health/peptides-unregulated-influencers

6. Honest Peptide. "How to Read a Peptide COA (Real vs Fake)." 2025. https://honestpeptide.com/research/how-to-read-a-peptide-coa

7. Janoshik Analytical. Third-Party Peptide Testing and Verification. https://janoshik.com/

8. Cernum Biosciences. "Avoid These Peptide Scams That Cost Buyers Thousands." 2025. https://cernumbiosciences.com/blogs/peptide-science-guide/avoid-these-peptide-scams-that-cost-buyers-thousands

9. Holt Law. "The Unregulated World of Peptides: What You Need to Know Before You Inject." 2025. https://djholtlaw.com/the-unregulated-world-of-peptides-what-you-need-to-know-before-you-inject/

10. Verified Peptides. "Why Laboratory Validation Matters in Peptide Quality." 2025. https://verifiedpeptides.com/knowledge-hub/why-laboratory-validation-matters-in-peptide-quality/