How to buy research peptides from China

A practical sequence for first-time and repeat buyers. The goal is not the lowest quote — it is a shipment you can defend with documents.

1. Qualify the supplier before the product

Ask for the business licence, the bank account name and the invoice entity. They must match. A supplier that cannot align these three is a reseller with no control over production.

2. Send a structured RFQ

SKU list with strengths and quantities
Destination country and port/city
Documentation requirements (COA, MSDS, certificate of origin)
Packaging and labelling requirements
Target delivery window

A vague "price list please" gets a vague answer. A structured RFQ gets a quotable one.

3. Ask for the batch COA before payment

The COA must be for the lot you will receive, with HPLC chromatogram and MS spectrum. If the supplier sends a generic product COA, treat it as a warning.

4. Sample before volume

For a new SKU or a new supplier, order a sample lot and test it in your own workflow. The sample's COA batch number must match the shipment. How much to order, how to code it and what to test is set out in ordering a qualification sample.

5. Agree Incoterm and payment

Term	Who arranges freight	Risk transfer
EXW	Buyer	At supplier premises
FOB	Buyer (after loading)	On board
CIF	Supplier	At destination port
DDP	Supplier	At buyer's address

For first orders, T/T against documents is common. Credit terms come after a track record. Tie the balance to a document pack rather than to a promise of shipment, and verify any change of beneficiary details by callback — see supplier payment terms.

6. Prepare for customs

Confirm the commodity description, HS code and any import permit requirements in your country before shipment. Under-declaration is the buyer's legal risk, not a saving.

7. Verify on receipt

Batch number on vial matches COA and invoice
Packaging intact, cold chain maintained
Appearance consistent with the COA
Retain samples for your own records

What goes wrong most often

Not product quality — documentation mismatch. The vial says one batch, the COA says another, and the buyer cannot prove what was shipped. Build the paper trail before you build the order.

Research use only. This guide is commercial due diligence, not legal or medical advice.

Editor's take

The sequence matters more than the price. Buyers who qualify the entity, sample the lot and review the documents before paying consistently get fewer surprises than buyers who negotiate hardest.

Sources & evidence

Specification and analytical expectations: ICH Q6B / Q2(R1) — ICH quality guidelines.
API manufacturing quality systems: ICH Q7 — same ICH page.
Chinese national standards: GB/T via the SAMR full-text platform.

Commercial due diligence guidance, not legal advice; supplier claims must be verified against batch documents.

Limitations

This is commercial due diligence guidance, not legal advice. Supplier claims must be verified against batch documents and, where required, an independent audit.