How to assess a UK research-compound supplier

One question separates suppliers faster than any other:

"Can you send me the Certificate of Analysis for the specific lot number I will receive, including the chromatogram and the mass spectrum?"

It is specific enough that a generic response is visibly non-responsive. A supplier operating real batch control answers with a document; one operating on a single representative certificate has to reframe the question.

What to do with the answer is covered in how to read a COA and red flags on a peptide COA.

Compare what is claimed against what is shown:

• Is a purity figure accompanied by a method — column, gradient, wavelength?
• Is there an actual chromatogram, or only a number?
• Is identity confirmed by mass spectrometry, with theoretical and observed masses stated?
• Is net peptide content mentioned anywhere at all? Almost nobody reports it, so a supplier who does is signalling something real.

A site that publishes analytical detail is accepting the risk of being checked. That willingness is itself the signal, more than any individual number.

In the UK, the framing a supplier uses tells you how carefully they are operating. Two things are worth looking for:

• Consistent research-use-only positioning. Unlicensed medicines cannot lawfully be advertised to the public in the UK, and the MHRA applies those restrictions to websites and social media alike. A supplier making therapeutic claims about unlicensed compounds is either unaware of that or ignoring it, and neither is reassuring about the rest of their operation.
• Accurate control status. Some compounds sit under the Misuse of Drugs Act 1971 or are prescription-only medicines. A supplier who is straightforward about which is which is more likely to be straightforward elsewhere. Are peptides legal in the UK? covers the framework.

Basic and quickly done:

• Is there a registered company name and number, verifiable at Companies House?
• Is there a real address and a working contact route that produces a human response?
• Do the terms, returns and privacy pages exist and say something specific, or are they generic boilerplate?
• Is the domain consistent with the business name and long-established, rather than newly registered?

None of these proves quality. All of them are trivially cheap for a legitimate operation to satisfy and slightly inconvenient for a temporary one.

Reviews in this market carry less information than in most, for two reasons. First, buyers usually cannot verify what they received — a positive review generally reports that a parcel arrived, not that the contents were analytically correct. Second, incentivised and fabricated reviews are common enough to contaminate the signal.

Since the Digital Markets, Competition and Consumers Act 2024 came into force, publishing fake reviews or concealing incentivised ones is explicitly unlawful in the UK. That is a useful floor, but it does not make an unverifiable positive review informative. Weight reviews for service facts — dispatch, packaging, responsiveness — and weight documentation for everything else.

The final check is empirical and cheap. A first order at minimum quantity establishes several things that no amount of site-reading will:

• Whether the vial is actually lot-marked.
• Whether the lot number matches the COA they send.
• Whether packaging protects the material and whether any stated cold-chain claim is honoured.
• Whether a specific technical question receives a specific answer.

That last one is more diagnostic than it sounds. A supplier who can answer a question about counterion, solubility or storage without deflecting into sales language is demonstrating competence that cannot be faked in the way a certificate can.

1. Lot-specific COA available on request — with chromatogram and mass spectrum.
2. Analytical method stated, not just a percentage.
3. Identity confirmed by MS against a stated theoretical mass.
4. Consistent research-use-only framing; accurate on UK control status.
5. Verifiable company identity and a working contact route.
6. Specific technical answers to specific technical questions.
7. Vials physically marked with lot numbers on arrival.

NMChem's own implementation of the first point is the COA database; the same checklist should be applied to it as to anyone else's.