Research-use information only. The peptides discussed are laboratory reference materials, not for human or animal consumption.
Peptides are fragile molecules. Stored correctly they remain stable for a long time; stored badly they degrade and your reference material is no longer reliable. The rules differ sharply depending on whether the peptide is still a freeze-dried powder or has been reconstituted into liquid.
Lyophilised (powder) — long-term stable
- Freezer (-20 °C): typically stable for around 24 months.
- Fridge (2–8 °C): stable for several months.
- Room temperature: fine for shorter periods and, importantly, for the few days a parcel spends in transit.
This is why heat exposure during shipping is not the concern people assume — the powder form is robust over the days it is in the post. Reconstitute only when you are ready to use it.
Reconstituted (liquid) — use within weeks
- Fridge (2–8 °C), protected from light: generally 3–4 weeks when prepared with bacteriostatic water (the benzyl alcohol preservative is what extends this window).
- Prepared with non-preserved water, the usable life is much shorter.
The freeze–thaw rule
Do not repeatedly freeze and thaw a reconstituted vial. Each cycle stresses and degrades the peptide. If you must freeze liquid solution for longer storage, aliquot it into single-use portions first so each is thawed only once.
Quick reference
| Form | Storage | Approx. shelf life |
|---|---|---|
| Lyophilised powder | -20 °C freezer | ~24 months |
| Lyophilised powder | 2–8 °C fridge | Several months |
| Reconstituted liquid | 2–8 °C, dark | 3–4 weeks |
Practical habits
- Keep powder in the freezer; move to fridge only what you are about to prepare.
- Always protect reconstituted vials from light.
- Label every reconstituted vial with concentration and date.
- Check the batch COA before use — degraded or mishandled material will not match its original report.
See our full handling guides or browse COA-verified stock.