How to choose a research peptide supplier — 7 quality criteria

The research peptide market is fragmented, and the difference between a good source and a random one rarely comes down to "which peptide" — it comes down to documentation and the supplier's credibility. Below are seven criteria by which you can recognise a source that can genuinely be verified.

1. A COA for the specific batch (HPLC + MS)

A certificate of analysis (COA) should be tied to the batch number (LOT) you actually receive — not one document from two years ago attached to the entire catalogue. A sound COA combines HPLC (purity) with mass spectrometry (confirmation of the molecule's identity). We describe how to read such a document in our guide: how to read a COA.

2. Safety data sheets (SDS)

A safety data sheet contains the CAS number, molecular weight, storage conditions and handling instructions. Its presence shows that the supplier treats the material as a research reagent rather than anonymous powder. Our sheet centre: SDS safety data sheets.

3. A matching CAS number and molecular weight

The CAS number and molecular weight on the COA must match the reference data for the substance. It is a simple test that filters out mistakes and substitutions.

4. A real entity that issues invoices

A registered company with an address and an invoice gives you a point of reference if something goes wrong. An anonymous seller on a messaging app does not. It is also a matter of the legality of the transaction and of accountability.

5. Storage and transport conditions

A good supplier can tell you how the material was stored and how it is shipped. Lyophilizate is stable at room temperature for the duration of transit, but the way it is packed and the storage information provided are a quality signal. See: storing peptides.

6. Transparent communication, no pressure

A sound source answers questions about batch documentation and promises no health effects or "uses in humans". Research materials are research materials — anyone suggesting otherwise is crossing a line that should concern you.

7. Shipping and payment without risk

For buyers in the EU, a supplier inside the Union means no customs clearance and no risk of a parcel being held. Payment by standard methods (card, bank transfer) and an invoice are further elements of credibility.

In short

Instead of asking "where to buy", ask "show me the batch COA, the SDS and the invoice". A supplier who has them is verifiable — the rest is a lottery. The full catalogue of materials with documentation is in the shop, and there is more in the knowledge base.

Materials for research purposes only. Not for human or animal consumption. We do not advise on use.