A certificate of analysis (COA) records the results of tests on one lot of a material. But who carried out those tests matters as much as the results themselves. Two kinds of document are common in research peptide supply: the manufacturer's certificate and a report from an independent laboratory. This guide explains what each one is, what each can and can't tell you, and where Vitaluxe Labs stands today.
It's a guide to reading documents. It doesn't cover handling, preparation or use of any material, and we don't provide instructions of that kind.
What a manufacturer COA is
A manufacturer COA is issued by the company that made the material. It's usually produced as part of the manufacturer's own release testing: the lot is tested against a set of specifications, and the certificate records the specification and the result for each test.
A typical manufacturer certificate lists:
- the product name, lot number and report date
- each test item (for example appearance, identity by MS, purity by HPLC) with its method
- the specification for each test, next to the result for that lot
- the manufacturer's stated storage conditions
What it tells you: what the manufacturer measured on that lot, by which methods, and against which limits. It's the primary record of how the lot was released.
What it doesn't tell you: whether anyone outside the manufacturer has measured the same lot. The certificate is the manufacturer's own account of its own product.
What independent testing is
Independent testing means a laboratory with no stake in the sale analyses a sample. The sample may come from the manufacturer, the seller or a buyer, and the report is issued in the laboratory's own name.
When you read an independent report, a few details help you judge it:
- Who commissioned it, and whose name is on it. Some reports carry the name of the seller who sent the sample; others are anonymous.
- Which sample was tested. A report covers the sample the laboratory received. Check whether it identifies a lot, and whether that lot matches the one you're interested in.
- The methods and their scope. Independent reports often cover identity, purity and sometimes the amount of material in a vial. They may not repeat every row on a manufacturer's certificate.
- The laboratory's standing. Some laboratories hold formal accreditation for specific test methods (ISO/IEC 17025 is the international standard for testing laboratories). Accreditation applies to named methods, not to everything a laboratory does, so check what it covers.
- Whether the report can be checked with the laboratory. Some laboratories let you look a report up by a reference code.
What it tells you: a second, separate measurement of a sample by a body that didn't make or sell it.
What it doesn't tell you: anything about other lots, or about samples it didn't test. Like a manufacturer certificate, it describes only what was tested.
Side by side
| Question | Manufacturer COA | Independent report |
|---|---|---|
| Who issues it? | The maker of the material | A separate laboratory |
| Which material does it cover? | The lot printed on it | The sample the laboratory received |
| Is it routine for every lot? | Usually, as part of release testing | Only when someone commissions it |
| Typical scope | Full release specification | Varies; often identity and purity |
| Main limitation | The issuer is also the maker | Covers only the sample tested |
Neither kind of document is a guarantee about a particular vial. Each is a record of a specific test on a specific lot or sample. The most useful habit is the same for both: check who issued it, which lot or sample it covers, and which methods were used. Our guide to HPLC vs LC-MS explains what the two most common methods show.
Where Vitaluxe Labs stands today
We want to be plain about this, because it's the question this article exists to answer.
- Our certificates are manufacturer COAs. We publish Manufacturer COAs (SENOBIO), listed by product, where available, on our COAs page. Our vial labels don't currently show a lot number, so a certificate may not be for the lot you receive. They're SENOBIO's own documents, and we describe them that way.
- We don't currently publish independent test reports. None of the certificates on our site is an independent or third-party report, and we don't describe them as one.
- A certificate relates to the lot printed on it. Our vial labels don't currently show a lot number, so we can't yet confirm which lot a vial came from.
We'd rather you judge our documents for what they are than read more into them than they say.
Questions worth asking any supplier
Whoever you buy from, these questions apply to the documents they show you:
- Who issued this certificate, and on what date?
- Which lot does it cover, and how does that lot relate to what's on sale?
- Is it a manufacturer certificate or an independent report? Does the supplier say which?
- Which methods were used for identity and purity?
- If it's an independent report, whose name is on it, and can it be checked with the laboratory?
Our guide to checking a UK research peptide supplier puts these questions alongside the other things worth looking for, such as business details and policies.
Further reading
- How to read a peptide certificate of analysis: each row of a certificate, explained
- Our COAs page and FAQ
- The full range in Research Peptides UK
Sources
Accessed 6 October 2026.
- Manufacturer COAs (SENOBIO), listed by product, where available, on our COAs page. Our vial labels don't currently show a lot number, so a certificate may not be for the lot you receive. Cited for the general layout of a manufacturer certificate only.
- ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (International Organization for Standardization). Named as a standard only.
For laboratory research use only. Not for human or veterinary use. 18+
