Quality
How to Read a Certificate of Analysis (And Spot a Fake One)
A COA is the only document standing between you and an unverified vial. Most people never read theirs. Here is exactly what to check, in order.
In this article
A certificate of analysis is the only piece of evidence that connects the vial in your hand to a test that was actually performed. It is also the document almost nobody reads, which is precisely why bad actors keep getting away with issuing convincing-looking ones.
What a COA is
A COA is a report from an analytical laboratory stating what was tested, by what method, and what the result was. A legitimate one is specific to a batch — a lot — and it is dated. It is not a marketing sheet, it does not have a hero image on it, and it does not describe benefits.
The two tests that matter for peptides are HPLC and LC-MS. They answer two different questions, and a COA with only one of them answers half the question.
HPLC: the purity number
High-performance liquid chromatography separates a sample into its components and measures the relative area of each. The headline number — 99.2%, say — means that 99.2% of the detected material corresponds to the main peak.
The critical nuance: HPLC tells you how pure the sample is, not what it is. A 99.5% pure vial of the wrong compound will produce a beautiful HPLC trace. Purity alone proves consistency, not identity.
You should also see the chromatogram itself, not just the number. The trace shows you where the impurities sit and whether there is a second peak large enough to matter.
LC-MS: the identity check
Liquid chromatography mass spectrometry measures molecular mass. Every peptide has a known, calculable molecular weight based on its amino acid sequence. If the measured mass matches the theoretical mass within tolerance, the molecule is what it claims to be.
This is the test that catches substitution. A vendor shipping a cheaper peptide under an expensive label passes HPLC comfortably and fails LC-MS immediately. If a COA has no mass spec, it has not answered the question you most need answered.
The five things to check, in order
- Does the lot number on the certificate match the lot number on your vial? This is the single most common failure. A generic COA for "the product" rather than for your specific batch is not evidence about your vial.
- Is there a mass spec result, and does the observed mass match the theoretical? Both numbers should be printed. If only "identity confirmed" appears with no figures, that is a summary, not a result.
- Is the testing laboratory named, with contact details? An independent lab has a name, an address and a report number. "Tested in-house" is not third-party testing.
- Is it dated, and is the date plausible? A COA dated years before your vial was manufactured is describing a different batch.
- Is the chromatogram included? A number without the trace behind it is an assertion. The trace is the evidence.
How fake COAs usually fail
Forged certificates are rarely sophisticated. The recurring tells are the same handful of things: no lot number or a lot number that matches nothing; a purity figure with no chromatogram; a lab name that returns nothing when searched; a mass spec section that says "conforms" without printing a mass; and a suspiciously round purity number repeated identically across every product in a catalogue.
That last one is worth dwelling on. Real batches vary. A vendor whose every product is exactly 99.9% pure is not running tests, they are running a template.
What we do
Every lot we release is sent for independent HPLC and LC-MS analysis before it enters inventory. The certificate for your specific lot number ships in the box. If a lot does not clear, it does not get sold — it does not get quietly blended into the next batch either.
Compounding is done by US state-licensed pharmacies. That matters because a licensed compounding facility is subject to state board inspection and USP standards for sterile preparation, which an unregulated overseas supplier is not.
Ask for it
Whoever you buy from, ours included: ask for the COA for the lot you are being sold, before you pay. A vendor who has one will send it in minutes. A vendor who does not will explain why they cannot.
That single question filters out most of the industry.
Research Use Only. All products sold by MaxSpan Peptides are supplied strictly for in vitro laboratory research by qualified professionals aged 21 or older. They are not intended for human or animal consumption, clinical use, diagnostic use, veterinary application, or any therapeutic purpose. Statements made on this website have not been evaluated by the U.S. Food and Drug Administration. MaxSpan Peptides is a chemical supplier and is not a compounding pharmacy as defined under Section 503A of the Federal Food, Drug, and Cosmetic Act, nor an outsourcing facility as defined under Section 503B.
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