Documentation is what separates a research-grade purchase from a blind guess. Below is a plain-language walkthrough of the documents and labels that typically accompany a legitimate research peptide order, and what each one is meant to tell you.
Certificate of Analysis (COA)
A COA reports the analytical testing performed on a specific batch — typically HPLC purity percentage and mass spectrometry confirmation of molecular identity. The COA should reference a lot or batch number that matches what's printed on your vial, not a generic document reused across every batch ever produced.
Vial and packaging labels
Labels should identify the compound name, net content or concentration, lot number, and a "research use only" designation. Consistency between the label, the listing you ordered from, and the COA is what confirms you received what you paid for.
Storage instructions
Look for a specific temperature range (e.g., stored at -20°C) rather than a vague "keep cool" instruction. Specificity indicates the supplier has actually characterized the product's stability rather than applying boilerplate text.
Safety data sheets (SDS)
Where available, an SDS outlines handling precautions relevant to laboratory use. Not every peptide supplier publishes one, but its presence is a positive signal of documentation maturity.
Batch lookup tools
Some suppliers offer a lot-number lookup on their site so a COA can be retrieved independently of the paperwork shipped in the box. This is a useful cross-check, particularly for records you intend to keep for longer-term research logs.
Putting documentation to use
Keep a simple record per order: date received, lot number, COA, and storage conditions on arrival. Over multiple orders, this record becomes a useful reference for tracking consistency across batches and suppliers.