What to check before you buy research peptides

Ask the supplier for a certificate of analysis, or COA, for the batch you are buying. The COA must carry a batch ID. That ID must match the batch number printed on the vial. If the numbers do not match, the certificate does not apply to your material.

The COA should show identity as well as purity. HPLC purity alone does not prove the sequence. HPLC is a method that sorts the parts of a sample. Identity needs mass spectrometry or a characterised reference standard. Mass spectrometry checks that the measured weight matches the peptide you ordered.

Check the basics of the transaction. Look for a registered company. Look for a working contact route. Look for stated dispatch and packaging practice. Look for a research-use-only posture. A supplier that implies human use should fail your checklist. A supplier that publishes forum dosages should fail it too. So should a supplier that hides who it is.

Keep the paperwork. Store the COA with the vial. Record the batch ID in the laboratory notebook. That one habit turns a purchase into an auditable, reproducible research input.

All products referenced in this article are supplied strictly for laboratory research use only. They are not medicines, are not licensed or approved for human or veterinary consumption, and must not be administered to humans or animals. Nothing in this article is medical advice. Researchers are responsible for operating within their own institution's and jurisdiction's applicable regulations.