← Research Library · Published August 30, 2026
Peptides are supplied lyophilized — freeze-dried to a dry powder — because that form is far more stable than a solution. How they are stored before and after reconstitution has a direct effect on how long they remain usable for research. The guidance below is general laboratory practice; always defer to the stability data for the specific compound.
Lyophilized powder
- Cold, dark, dry. A common approach is −20 °C for medium-term storage and −80 °C for long-term. Keep vials sealed and away from light and moisture.
- Let vials reach room temperature before opening. Opening a cold vial lets humid air condense inside it, which introduces water the freeze-drying removed.
- Minimise handling. Every open-and-close cycle is an opportunity for moisture ingress.
After reconstitution
- Refrigerate. A reconstituted peptide is a solution and is less stable than the powder. Most are kept at 2–8 °C and used within a limited window.
- Avoid repeated freeze-thaw. If a solution must be frozen, aliquot it first so each portion is thawed only once. Freeze-thaw cycling degrades many peptides.
- Use bacteriostatic water for multi-draw vials. It contains a preservative (benzyl alcohol) that inhibits bacterial growth in a vial accessed more than once. Plain sterile water has none. See the reconstitution walkthrough.
- Label and date every aliquot with the compound, concentration, diluent, and date prepared.
Shelf life
Lyophilized peptides stored correctly often remain stable for a year or more; reconstituted solutions are measured in weeks, not months. These are ranges, not rules — sequence, formulation, and storage temperature all matter, and the compound’s own stability data is the authority.
On arrival
When an order arrives, move the vials into cold storage promptly and record the batch/lot numbers against the Certificates of Analysis before the vials go into the freezer, while the paperwork is in front of you.
FAQ
How long do reconstituted peptides last?
It depends on the specific peptide, the diluent, and the storage temperature. Kept refrigerated and protected from repeated freeze-thaw, many peptides remain usable for a number of weeks — check the stability data for the compound you are working with.
Do lyophilized peptides need cold-chain shipping?
Lyophilized (freeze-dried) peptide powder is generally stable at ambient temperature for the duration of standard shipping. Move it to cold storage on arrival.
For Research Use Only. All compounds sold by Summit Labs are intended solely for in vitro research and laboratory use. Not for human or veterinary consumption. Must be handled by qualified researchers in compliance with all applicable regulations.