Information only. We do not sell products or give medical advice. Consult a licensed physician / healthcare professional.
Before anything else, a peptide should be verified against a real Certificate of Analysis — an independent lab document reporting purity, identity, and contaminants for one specific batch. This site teaches you to read every field. Information only — we do not sell.
Fundamentals
A COA is a laboratory document reporting the identity and purity of one specific batch of material. It only carries weight when an independent, accredited lab issues it — not the seller.
A serious Certificate of Analysis names the compound and sequence, references the exact lot number, reports purity by HPLC with an attached chromatogram, confirms identity by LC-MS, and lists water content (Karl Fischer) and endotoxin (LAL). Every claim ties back to a named laboratory and its accreditation. A generic sheet with no lot number, no chromatogram, and no issuing lab is not a COA — it is marketing.
Signature · interactive reader
Below is a specimen COA. Select any field to reveal what it means in plain English and the red flag that should stop you. This specimen is illustrative — values are for teaching only.
Select a field to decode it — hover, click, or use the keyboard.
The full product name and, ideally, the amino-acid sequence or an unambiguous identifier. It must match exactly what was ordered — the trade name alone is not enough.
Only a marketing name appears, the sequence is absent, or the name does not match the label on the vial.
The traceability key. This exact lot number must appear both on the vial and on the COA, tying the analysis to your specific material.
There is no lot number, or the number on the certificate does not match the number on the label. A generic COA proves nothing about your unit.
When the batch was made and by when it should be re-tested or discarded. The analysis date should be contemporary with, or after, manufacture.
Dates are missing, the analysis predates manufacture, or an old COA is reused for a newer batch.
A physical description of the material and, sometimes, its appearance on reconstitution. A simple but real quality checkpoint.
The field is blank, or the description does not match what is actually in the vial (colour, clarity, particulates).
The quantitative purity of the target compound, measured by HPLC. ≥98% is the commonly cited research threshold, and the chromatogram should be attached so the main peak and area percentage are visible.
A bare number with no chromatogram, an impossible value such as 100.0%, or purity below the stated specification with no explanation.
Confirmation of molecular identity by mass. The found mass — commonly the [M+H]+ ion — should match the expected monoisotopic mass, proving the molecule is what it claims to be.
No mass spectrum is provided. HPLC purity without LC-MS can be 98% of the wrong molecule.
Residual water measured by Karl Fischer titration. Lyophilized peptides retain water, which lowers the true net peptide mass and matters for any accurate research work.
The field is simply absent — a common omission that hides part of the real composition.
Bacterial endotoxin measured by the LAL assay and reported in endotoxin units. It matters wherever a research material would contact cells or be injected in a study.
No endotoxin result appears, especially for material intended for cell culture or in-vivo research.
The conditions under which the reported specifications hold. Storage guidance is part of what keeps the certified values valid over time.
No storage conditions are stated, making the retest date and stability claims impossible to interpret.
Verification
Faked, recycled, and vendor-issued certificates share recognizable patterns. Compare the two columns field by field before you trust any document.
Analytical standards
A complete certificate reports purity, identity, water, and endotoxin — four measurements, four methods. Any one missing leaves the picture incomplete.
The proportion of target compound, with the chromatogram attached so the main peak is visible.
Molecular mass confirmation proving the compound is what the label claims — not an analogue.
Residual water content, which lowers the true net peptide mass in lyophilized material.
Bacterial endotoxin in EU/mg or EU/mL — relevant for any cell-culture or in-vivo research use.
Independence
The objectivity of a COA depends entirely on the independence of whoever issues it. This is the single most important thing to check.
A seller issuing its own COA is grading its own work. In-house "QC" is not the same as an independent, accredited laboratory. Only a third-party lab — ideally ISO/IEC 17025 accredited — produces a certificate free of commercial incentive, using validated and auditable methods.
Independent testing services such as Janoshik-style labs exist precisely to close this gap: they analyse a submitted sample and report the result without a stake in the sale.
Framing: ISO/IEC 17025 · WHO quality principles · USP/pharmacopeial methods. Updated July 2026.
Regulatory context
This is a global resource, so the reference points are international: quality principles and pharmacopeial methods recognised across borders — never a claim of consumer safety.
The World Health Organization sets broad quality and safety principles; ISO/IEC 17025 governs laboratory competence; and pharmacopeial references such as the USP describe validated analytical methods (for example endotoxin testing conventions). Together they form the vocabulary a serious COA speaks.
Sources: who.int · ISO/IEC 17025 · usp.org. Updated July 2026.
Peptides discussed here are research materials where applicable — not consumer goods and not approved medicines. Legal status varies by country. Nothing here recommends use, dose, or a source of supply. Anyone considering these substances should consult a licensed physician who can assess their individual situation.
Questions
A Certificate of Analysis is a laboratory document that reports the identity and purity of one specific batch of material. It is only meaningful when issued by an independent, accredited laboratory — not by the seller. A serious COA reports purity by HPLC (typically ≥98%), confirms identity by LC-MS, and references the exact lot number tested.
For research work, purity of at least 98% measured by HPLC is the commonly cited threshold, with identity confirmed by LC-MS. The HPLC chromatogram should be attached so the main peak and its area percentage can be seen, not just a headline number.
A seller cannot objectively certify its own product. Only an independent laboratory — ideally ISO/IEC 17025 accredited — issues a COA free of conflict of interest, using validated, auditable methods. Without independent analysis there is no guarantee of identity, purity, or the absence of contaminants.
HPLC quantifies purity as a percentage of the target compound. LC-MS confirms molecular identity by measuring mass (for example the expected [M+H]+). You need both: HPLC alone can show 98% of the wrong molecule, and MS alone does not quantify purity.
No. Peptide COA is an information and education resource. We do not sell products, do not capture email, and do not give medical advice. The material simply teaches how to read and verify a Certificate of Analysis. Consult a licensed physician before considering any use.
How to read a COA from top to bottom, how to judge an independent ISO/IEC 17025 lab, and how to spot a faked certificate. Direct download — no form, no signup.
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Editorial authority
Editorial team
All content is produced by an editorial team specialising in scientific and regulatory communication. Nothing published here is medical advice. Sources are documented, and regulatory context is reviewed and updated. See how we review our work in the methodology.
Sources & references
This site provides general information for educational purposes only. It is not, and does not replace, medical advice, diagnosis, or treatment. Research peptides are not approved medicines. Any consideration of their use must involve a licensed physician or healthcare professional, who alone can assess an individual situation.
→ Consult a licensed physician / healthcare professional
Articles
Five technical guides on reading, proving, and verifying a peptide COA.
COA Anatomy
A field-by-field walkthrough of a real Certificate of Analysis.
Read articleAnalytical Methods
Purity versus identity — and why you need both to trust a COA.
Read articleVerification
Nine concrete red flags of faked, recycled, and vendor-issued certificates.
Read articleLab Accreditation
Why accreditation — not a vendor's word — is what makes a lab credible.
Read articleHidden Fields
The COA fields most certificates quietly leave out — and why they matter.
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