What is a peptide COA?

A certificate of analysis (COA) is a document from a testing laboratory reporting what a sample actually contains — typically the peptide's identity (is it the right molecule?) and its purity (what percentage of the sample is that molecule). For research peptides, a third-party COA is the only objective evidence of what's in the vial; everything else is a vendor's word.

What purity should a research peptide COA show?

Most reputable research-peptide COAs report purity by HPLC, and figures in the high-90s percent are common for quality material. But a purity number is meaningless without an identity test (mass spec) confirming it's the correct molecule — 99% pure of the wrong compound is still useless. Always read identity and purity together.

How do you spot a fake COA?

Red flags include: no testing lab named, no method listed (HPLC/MS), a batch or lot number that doesn't match the product, a purity figure with no supporting chromatogram, reused lab letterhead across unrelated products, and dates or sample names that don't line up. When in doubt, contact the named lab directly to confirm the report exists.

How to Read a Peptide COA (and Spot a Fake) — A Plain-English Guide

Short answer: A certificate of analysis (COA) is a lab document that tells you two things about a research-peptide sample — what it is (identity) and how pure it is (purity). A real one names the testing lab, lists the method, shows a batch number that matches your product, and ideally includes the raw chromatogram. If any of those are missing, you’re looking at a marketing graphic, not proof.

In a market with no FDA oversight and a long history of exit scams, the COA is the closest thing to ground truth you have. This guide shows you how to read one like the lab did — and how to catch the fakes.

The two questions every COA must answer

A useful COA answers both of these. One without the other tells you almost nothing.

Identity — is it the right molecule? This is usually confirmed by mass spectrometry (MS). The report shows the measured molecular mass against the expected mass for that peptide. If they match, the vial contains what the label claims. If there’s no identity test at all, purity is irrelevant — you could have a 99% pure batch of the wrong compound.
Purity — how much of the sample is that molecule? This is measured by HPLC (high-performance liquid chromatography). The result is a percentage: what fraction of the detected material is the target peptide versus impurities, fragments, or leftover synthesis reagents.

Read them together, always. “99% pure” with no identity test is a number floating in space.

How to actually read the document

When you open a legitimate COA, look for these fields and check that they’re internally consistent:

Testing laboratory name — a real, nameable third party (independent analytical labs are the norm in this space). No lab named = no COA.
Method — it should say how the numbers were produced: HPLC for purity, MS for identity. “Purity: 99%” with no method is an assertion, not a measurement.
Batch / lot number — this must match the lot on the product you actually received. A COA for a different batch tells you nothing about your vial.
Sample name & date — the compound named on the COA matches the product; the test date is plausible and recent relative to the batch.
The chromatogram — the best COAs include the actual HPLC trace (a graph of peaks). One dominant, clean peak is what high purity looks like; a forest of smaller peaks means impurities the headline number may be hiding.

The fakes: what forged and recycled COAs look like

Faked and “borrowed” COAs are common. The tells are usually structural, not subtle:

No lab named, or a lab that won’t confirm the report. Reputable labs will verify whether a report number is genuine if you ask. Forgers count on you never checking.
A purity percentage with no chromatogram and no method. A number on a branded graphic is marketing. A measurement comes with how it was measured.
Mismatched batch numbers. The COA’s lot doesn’t match the product’s lot — a real document for an unrelated (or imaginary) batch, reused to create the impression of testing.
Recycled letterhead. The same lab header and layout stamped across products that would never have been tested together, often with the only change being the compound name typed in.
Identity quietly missing. Plenty of fakes show a confident purity figure and simply omit the mass-spec identity result — the harder one to fake — hoping you won’t notice it’s gone.

When something feels off, do the one thing forgers don’t expect: email the named lab with the report number and ask if it’s real.

Why this is the whole game

You cannot taste, see, or feel the difference between a correctly synthesized research peptide and an underdosed, impure, or wrong one. The COA is the only window into the vial. A vendor that publishes a complete, third-party, batch-matched COA for everything it carries is making a verifiable claim. A vendor that shows you a testimonial, a star rating, or a glossy “lab-tested ✓” badge with no document behind it is asking for your trust without earning it.

That’s the entire reason this site exists: receipts over reviews. Learn to read the document, and you stop being a target.

Educational, research-use-only. This article explains how to interpret laboratory documents; it is not medical advice, a dosing recommendation, or a claim that any compound is safe or effective for human use.