Cold-Chain Logistics and Peptide Stability in Transit

A common question on receiving a peptide order: did the material degrade in transit if it spent two days at room temperature? For lyophilized vials, the short answer is almost always no.

Why lyophilized survives ambient

Freeze-drying removes the water that drives most degradation pathways. With water activity below a few percent, peptide bonds are dramatically more stable to hydrolysis, oxidation, and microbial activity. Standard practice in the industry is to ship lyophilized peptides at ambient temperature with documented stability data supporting transit windows of one to two weeks.

On receipt

• For short-term storage (weeks), refrigerate at 2–8 °C.
• For long-term (months to years), freeze at -20 °C or below in the original sealed vial.
• Allow vials to reach room temperature before opening to prevent moisture condensation on cold powder.

After reconstitution

Reconstituted peptides are far less stable. Refrigerate immediately, and consult the COA or peptide-specific stability literature for the appropriate working window — typically days to a few weeks depending on the sequence, buffer, and pH.