How to Read a Peptide COA | Step-by-Step

COAs are built for analytical chemists. If you’ve ever opened one and thought “I see numbers, but what do they actually mean?” — you’re in the right place. We’re going to walk through a real Elutide COA section by section, using an actual batch of BPC-157, Lot E-1105559, tested by Horizon Analytical.

No jargon walls. No chemistry degree required. Just a clear breakdown of what every part means and what you should pay attention to. View the full COA referenced in this guide (PDF) →

Section 1: The Header

Who tested it, when, and for whom

The header is your first trust check. It tells you three things immediately: the laboratory that performed the testing, the client who commissioned it, and when the analysis happened.

Field	What It Means
Laboratory Name	The independent lab that performed the analysis. Should be a third-party facility — not the supplier’s own in-house lab. Elutide uses Horizon Analytical, a US-accredited laboratory.
Lot Number	The unique batch identifier. This should match the lot number on your product label. If it doesn’t, something is wrong.
Client Name	The company that submitted the sample. Confirms the supplier actually sent their product to a lab — not just downloaded a template.
Received / Conducted Dates	When the lab received the sample and when testing was performed. Confirms the analysis is recent and relevant to your batch.

What to look for: The lab should be an independent, accredited facility you can verify online. If a COA doesn’t name the lab, treat that as a red flag. Horizon Analytical’s results are searchable at horizonanalytical.com.

Section 2: Compound Identity

Confirming the peptide is what it claims to be

This section is the compound’s fingerprint. It confirms exactly what molecule was tested and gives you chemical identifiers to cross-reference in scientific databases.

Field	What It Means
Compound	The peptide name. Should match what you ordered.
Lot	Batch identifier. Should match your product label and the header above.
Appearance	Physical description. Most research peptides arrive as a white lyophilized (freeze-dried) powder. Discoloration can indicate degradation.
CAS Number	A globally unique chemical identifier. Look it up on PubChem to verify the compound independently.
Molecular Formula	The exact atomic composition. For BPC-157: C₆₂H₉₈N₁₆O₂₂ — a 15-amino-acid pentadecapeptide.
Molecular Weight	Mass per molecule in g/mol. Used in mass spectrometry to confirm identity — the detected mass should match.

What to look for: Every field filled in. Missing CAS or formula means the lab may not have done full identity verification. The CAS number is your best independent check.

Section 3: Test Results

The numbers that matter most

The core of the document. The methodology statement tells you what analytical techniques were used, and the results grid gives you the actual numbers.

Field	What It Means
Testing Methodology	The analytical techniques used. This COA uses UPLC with Mass Spectrometry — the gold standard for peptide analysis.
Compound Test	Identity confirmation. Spec and result should match — “BPC-157” in, “BPC-157” out.
Quantity	Labeled amount vs. actual. This batch specified 10mg and tested at 10.25mg — slightly over-filled, which is ideal.
Purity	The big one. What percentage is actually your target compound. Spec >98%, result 99.38%. Higher is better. Below 95% warrants scrutiny.
QR Code	Scan to verify the COA directly with the lab. One of the strongest authenticity features a COA can have — confirms the document is real, not fabricated.

Key takeaway: Purity tells you how clean the sample is. Quantity confirms you’re getting the labeled amount. Together they answer: “Is this the right compound, and is it pure?”

Section 4: UPLC Chromatogram

The visual proof of purity

If purity is a number, the chromatogram is the picture that proves it. UPLC separates the sample’s components and measures each one individually. The simple version: the sample gets pushed through a column at high pressure, different molecules exit at different speeds, and a detector plots a peak for each one.

What You See	What It Means
One tall, sharp peak	Your target compound. A single dominant peak means the vast majority of the sample is one substance. Exactly what you want.
Flat baseline	Very little noise or impurity in the sample. Clean baselines are good baselines.
X-axis (time)	Retention time in minutes. Each compound exits at a characteristic time, helping identify it.
ELSD label	Evaporative Light Scattering Detector — the detection method. It evaporates the liquid carrier and measures light scattered by remaining solid particles.

What to look for: One sharp, dominant peak with a flat baseline. Multiple peaks could mean impurities, degradation, or synthesis byproducts.

Section 5: Mass Spectrometry (MS)

Molecular-level identity confirmation

If UPLC answers “how pure is this?”, mass spectrometry answers “is this actually the right molecule?” It ionizes the compound and measures the mass-to-charge ratio (m/z) of the fragments. Think of it as a molecular weigh station — the machine sorts charged pieces by weight and plots what it finds.

What You See	What It Means
m/z peak clusters	Each peak is a molecular fragment at a specific mass-to-charge ratio. Dominant peaks should match the compound’s expected molecular weight.
Multiple charge states	Peptides like BPC-157 (~1419 g/mol) can carry multiple charges during mass spectrometry analysis. The detected mass-to-charge ratios confirm the molecular identity. Normal and expected.
Peak cluster pattern	A clean, well-defined cluster at the expected m/z range confirms identity. The spacing between peaks corresponds to predictable isotope distribution.

What to look for: Clear peak clusters at m/z values consistent with the molecular weight. If dominant peaks are at unexpected masses, the sample may not be what it claims. MS is the definitive identity test — much harder to fake than a purity number.

Section 6: Analyst Certification

The human behind the data

Every legitimate COA is signed by the analyst who performed or supervised the testing. This puts a real person — with real credentials — behind the results.

Field	What It Means
Analyst Name & Title	The scientist who oversaw testing. Credentials (PhD, title) indicate expertise level.
Signature	Personal accountability for the results. The analyst stakes their professional reputation on these numbers.
Methodology Statement	Formal confirmation that proper procedures were followed under standard laboratory conditions.

What to look for: A named analyst with verifiable credentials. No signature, no name, or just a generic stamp? That’s a lack of accountability.

Red Flags: When a COA Might Not Be What It Seems

What should make you ask more questions

Not every COA is created equal. Here are the warning signs that separate real documentation from window dressing.

Red Flag	Why It Matters
No lab name or “tested in-house”	Third-party testing removes the financial incentive to inflate results.
No chromatogram or spectrum	A purity number without supporting data can’t be verified.
Suspiciously round numbers	Real results have decimals. Exactly “99.00%” or “100%” should raise questions. Real testing gives you 99.38%.
No lot number	Without one, there’s no way to tie the COA to your specific batch. Could be reused across batches.
COA “available upon request”	Transparency issue. At Elutide, your COA ships with your order. Every time.
No QR code or verification link	Without one, you’re trusting the supplier’s word that the document is authentic.

The Elutide Standard

Every batch is independently tested at Horizon Analytical. Every order ships with a full Certificate of Analysis — UPLC purity, mass spectrometry identity confirmation, and endotoxin screening. Not upon request. In the box. We publish every COA to our library and include a scannable QR code so you can verify results directly with the lab.

That’s not a marketing claim. That’s the minimum standard we think every peptide supplier should meet.

Browse Our COA Library Shop The Collection

For Research Use Only. Not Intended for Human Consumption.
All Elutide products are intended for research purposes only. These products are not intended for human consumption, medical use, or as dietary supplements. They are not approved by the FDA.

This content is for educational purposes and does not constitute medical advice.

Related Research Peptides

Every Elutide peptide is independently tested at a US-accredited lab and ships with a full Certificate of Analysis. For Research Use Only. Not for human consumption.

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Every order below ships with the Certificate of Analysis this guide explains.

ELU-GLP2-TZ · SS-31 · IGF-1 LR3 · Oxytocin · AHK-Cu · PT-141 · Melanotan-2 · BPC-157 / TB-500 Blend · L-Glutathione · B12 (Cyanocobalamin) · Lipo-C / MIC-B12 · 5-Amino-1MQ

All products are for Research Use Only. Not for human consumption.

How to Read a Certificate of Analysis