Peptides are sensitive molecules, and how you store them has a direct effect on how long they remain usable. Proper storage protects both the identity and the purity of the compound, so later experiments reflect the peptide itself rather than degradation products.

Lyophilized powder: the stable state

In their freeze-dried (lyophilized) form, most peptides are relatively stable. Kept sealed and dry, lyophilized peptides can generally be stored in a freezer at around -20°C for extended periods, and for shorter durations in a refrigerator. The two biggest enemies are moisture and repeated temperature swings, so a frost-free freezer and a tightly closed vial go a long way.

After reconstitution

Once a peptide is dissolved into solution it becomes far more perishable. Reconstituted peptides are typically kept refrigerated and used within a limited window, because water accelerates chemical breakdown. Preparing only the amount you need, and keeping the rest lyophilized until required, helps preserve the stock.

Practical storage tips

• Store lyophilized vials sealed, dry and frozen (around -20°C) for long-term stability.
• Allow a frozen vial to reach room temperature before opening, to avoid condensation inside.
• Minimise freeze–thaw cycles; consider aliquoting if a peptide will be used repeatedly.
• Keep vials away from direct light and label them with the date received and opened.

Shelf life

Exact shelf life depends on the specific sequence and storage conditions, so always follow the guidance on the product’s documentation. When in doubt, a fresh HPLC check can confirm whether stored material is still within specification.

For laboratory and scientific research use only. Not for human or animal use.