For Research Purposes Only · Not For Human Consumption
A real Certificate of Analysis is a forensic document — signed, dated, traceable, and independently verifiable. This guide walks through the nine elements every legitimate peptide CoA must contain, the red flags that signal a fabricated certificate, and how to verify any lot you receive against the laboratory that issued it.
The single most useful thing a UK research lab can learn about peptide procurement is how to read a Certificate of Analysis with skepticism. A genuine third-party CoA from Janoshik Analytical or Aspen Bioanalytics is a high-trust document. A fabricated CoA from a grey-market supplier — produced on a laptop in five minutes using a stolen template — looks similar at first glance and is responsible for a significant share of failed experiments in the wider research-chemical market.
The difference between the two is forensic: signatures, lot numbers, dates, addresses, and analytical detail. None of these can be faked convincingly. Below is the checklist every research peptide CoA should pass before the vial it represents is used in an experiment.
The CoA must state the compound name (e.g. 'BPC-157') and a unique alphanumeric lot number that exactly matches the printed sticker on the physical vial. If the lot number on the vial does not appear on the certificate, the CoA is not for that material.
A numeric purity figure, ideally ≥98%, expressed as area-under-curve percentage. The result must be accompanied by the column type (typically C18), mobile phase composition (typically 0.1% TFA / acetonitrile), gradient profile, and detection wavelength (typically 214 nm).
An actual printed chromatogram showing the main peak and any minor impurity peaks. Without the chromatogram, the purity figure cannot be independently verified — and reputable labs always include it.
The observed mass-to-charge ratio of the dominant ion vs the theoretical mass of the named peptide, within standard tolerance. Many CoAs include the full MS spectrum; at minimum, a table showing observed vs theoretical mass is required.
The date the laboratory ran the test. This should be within weeks — not years — of the lot's synthesis date. A test date significantly earlier than the lot's claimed synthesis date is impossible and indicates a recycled certificate.
The full name and registered address of the independent laboratory. For UK research peptides this is typically Janoshik Analytical (Czech Republic), Aspen Bioanalytics, or Anresco Laboratories (USA). 'In-house testing' or 'tested internally' is not a third-party result.
A named analyst's signature (electronic or physical) confirms a real person at the testing laboratory takes professional responsibility for the result. An unsigned CoA, or one signed only by the selling supplier, is not a third-party verification.
A clear description of the analytical method — for HPLC, the column (e.g. ZORBAX SB-C18 4.6×150mm), mobile phase, flow rate, gradient and detection wavelength; for MS, the ionisation source (typically ESI+) and the instrument used. Without method detail, the result cannot be reproduced.
A unique report or document number assigned by the testing laboratory, so the certificate can be cross-referenced against the lab's own records. Most labs (including Janoshik) allow you to email the report number to confirm authenticity.
A private analytical lab in the East Midlands placed test orders with three UK research peptide suppliers and ran each lot independently against the supplied certificate. Two of the three certificates matched the in-house figures within standard tolerance — including the UK Peptides Retatrutide 10mg lot, which returned 99.2% in-house against 98.7% on the Janoshik certificate. The third supplier's "third-party CoA" turned out to be a fabrication: the report number was rejected by the named laboratory's authenticity check, and in-house HPLC revealed the lot was 91.4% pure with a significant truncation impurity at 8.3%.
The fabricated certificate looked competent — it had a chromatogram, a signature, a column reference. What it did not have was an authentic report number traceable to the named laboratory. One email exchange caught it.
Verification workflow
How HPLC and mass spec actually work
A plain-English walkthrough of the two analytical methods every peptide CoA depends on.
High-purity peptides for sale in the UK
Every UK Peptides lot above ≥98%, with the signed CoA linked directly on the product page.
Buying research peptides in the UK
Same-day Manchester dispatch, third-party verified, registered UK Ltd. The complete buyer's overview.
A Certificate of Analysis (CoA) is a laboratory report documenting the identity and purity of a specific lot of a chemical compound. For a research peptide, a complete CoA includes the compound name, lot number, the HPLC-UV purity figure, the ESI mass spectrometry identity confirmation, the test method (column, mobile phase, gradient), the analysis date, the name and signature of the analyst, and the address of the testing laboratory.
A first-party (in-house) CoA is produced by the same company selling the peptide. A third-party CoA is produced by an independent analytical laboratory — Janoshik Analytical, Aspen Bioanalytics and Anresco are the main labs UK research suppliers use. Third-party certificates are significantly harder to fake because the laboratory's signature, address and verification process are publicly known.
A genuine CoA carries a named analyst's signature, the testing laboratory's full address, an issue date within weeks of the lot's synthesis date, the actual HPLC chromatogram, the ESI-MS spectrum or table of observed vs theoretical mass, and the test method (column, mobile phase, gradient, detection wavelength). A document missing any of these is incomplete and should be treated as unverified.
Yes. Each synthesis batch must be tested independently because purity and identity can vary between lots. A supplier reusing a single CoA across multiple lots — or supplying a generic CoA without a matching lot number — is not providing meaningful verification. UK Peptides publishes a lot-matched CoA for every batch in stock.
The HPLC purity figure is the area under the main chromatographic peak expressed as a percentage of the total area under every detected peak in the UV trace. A figure of ≥98% means less than 2% of the UV-absorbing material in the vial is anything other than the named peptide. The figure is only meaningful if the chromatogram is printed on the CoA — otherwise it cannot be checked.
Mass spectrometry confirms identity. The peptide is ionised, accelerated through a magnetic field, and its mass-to-charge ratio measured. The observed mass is compared to the theoretical mass of the named peptide. A match within standard tolerance (typically ±0.1%) confirms the compound is what the label says it is. HPLC tells you how clean it is; MS tells you what it is.
Contact the testing laboratory named on the certificate (Janoshik Analytical or Aspen Bioanalytics) and supply the lot number printed on the CoA. The lab will confirm whether the certificate is genuine. You can also re-test a sample of any lot at any external analytical laboratory and compare the figure against the supplied CoA.