COA-Verified Peptides in the UK — What the Certificate Should Show
Searching for COA-verified peptides in the UK returns plenty of suppliers claiming 'certificates available' — far fewer publish a certificate of analysis for the specific batch they ship. This page explains what COA verification actually means, the two analytical tests behind it, and how to check a batch yourself.
What COA verification means
A certificate of analysis (COA) is the laboratory report for one specific batch of material. 'COA-verified' should mean that the exact lot you receive has been tested and that the certificate is tied to that lot by its batch number — not that a supplier holds a generic document somewhere, or one certificate reused across every batch of a product.
The two tests behind a verified batch
A credible peptide COA records two distinct results. Purity is measured by reversed-phase HPLC and reported as a percentage alongside the chromatogram, so you can see the main peak and any impurities. Identity is confirmed by LC-MS, comparing the detected mass against the expected mass for the target compound — the check that the vial contains the right molecule at all. Our guide on how research peptides are tested explains both methods in detail.
Published COAs beat 'COA on request'
Many suppliers offer certificates only on request, after you have ordered. The problems are practical: you cannot evaluate the batch before paying, the document arrives as a forwarded image that is trivially reusable, and you have no way to tie it to the vial in your hand. A supplier that publishes batch-level certificates — and lets you look a batch up by its lot number — moves the verification before the purchase, where it belongs.
How to verify by lot number
Every vial carries a batch / lot number on its label and certificate. Entering that number on the verify page returns the batch's own record: certificate of analysis, HPLC purity, LC-MS identity confirmation (expected versus detected mass), test date and storage conditions. Because the lookup is keyed to the lot number, the documentation you see is the documentation for that specific vial — see the step-by-step guide to verifying a peptide batch.
What a weak COA looks like
No batch or lot number; a purity percentage with no chromatogram; no identity (mass spectrometry) result; the same certificate appearing across different batches; or a supplier that will only forward an image and offers no independent lookup. Any one of these weakens the document considerably — our guide on reading a certificate of analysis covers the full field-by-field detail.
COA-verified peptides from Index Peptides
Every released batch in the Index Peptides catalogue is HPLC purity tested and LC-MS identity confirmed, documented per batch, and checkable by lot number on the verify page. Materials are dispatched from the United Kingdom and supplied strictly for in-vitro laboratory research — not for human or veterinary use of any kind.
Frequently asked questions
Where can I buy COA-verified peptides in the UK?
Index Peptides supplies research-use-only peptides from the UK with a per-batch certificate of analysis — HPLC purity and LC-MS identity confirmed — verifiable by lot number on the batch lookup page before or after ordering.
What does COA-verified mean for peptides?
It means the specific batch you receive has been analytically tested and the certificate is tied to that batch by its lot number — typically recording HPLC purity with a chromatogram and LC-MS identity confirmation — rather than a generic or reused document.
Are HPLC-tested peptides the same as COA-verified?
Not necessarily. HPLC measures purity only; it cannot confirm the vial contains the right molecule. A properly verified batch pairs HPLC purity with LC-MS identity confirmation, recorded against a lot number you can check.
Can I check a batch before ordering?
Yes — any released Index Peptides batch can be looked up by its lot number on the verify page, which shows its COA, HPLC purity and identity status, so verification happens before purchase rather than after.
What purity should a research peptide COA show?
Research peptides are commonly supplied at 98%+ by RP-HPLC, but the figure only means something alongside the chromatogram and an identity result — a sample can be 99% pure and still be the wrong compound.
Research use only. Not for human or animal consumption.