A high-purity peptide is only as good as the way it is kept. Temperature, light and moisture all degrade material over time - often invisibly. This is the general reference our own lab follows for storing lyophilized research peptides.
Freeze-dried powder is the most stable form. Kept frozen, dark and dry, sealed vials remain viable for extended periods. Cool room temperature is fine for short transit windows.
Refrigeration is appropriate when material will be drawn on soon. Keep the vial sealed and desiccated - at fridge temperatures the practical enemy is condensation on the cake, not heat.
Freeze-dried powder tolerates ambient temperature for the length of a normal shipment, which is why no temperature-controlled shipping is used. Move it to frozen storage on arrival.
These are general reference ranges, not a spec for a specific compound. Stability varies by peptide - some are notably more fragile than others. Where a product page or its Certificate of Analysis states a compound-specific condition, that always takes precedence over this general guide.
| State | Temperature | Protect from | Typical window |
|---|---|---|---|
| Lyophilized, sealed | −20 °C | Light, moisture | 18–36 months |
| Lyophilized, sealed | 2–8 °C | Light, moisture | Several months |
| Lyophilized, in transit | ≤ 25 °C | Prolonged heat | Days (shipping) |
| Lyophilized, seal broken | −20 °C | Humidity, air | Reduced |
| Oxidation-sensitive sequences | −20 °C | Light, oxygen | See COA |
General reference figures for laboratory handling. Not compound-specific guidance.
Repeated warming and re-freezing does more damage than a single stable temperature that is merely imperfect. A frost-free freezer cycles by design - a laboratory freezer that holds a steady −20 °C is the better choice.
Lyophilized powder is hygroscopic. Once ambient air reaches the cake it takes up water, and hydrolysis follows. Keep the seal and the desiccant intact, and let a frozen vial reach room temperature before opening so condensation forms on the glass rather than the powder.
Sequences carrying methionine, cysteine or tryptophan oxidize on exposure to light and air. These are the compounds whose effective shelf life is shortest, and the ones whose COA is worth reading closely for a sequence-specific note.
Shear and foaming denature peptides. Sudden agitation of the vial is avoidable stress on material that is otherwise stable, and it is the failure mode most often mistaken for a purity problem.
Research use only. This page describes laboratory handling of reference materials. Eon Peptides products are not drugs and are not intended for human or animal consumption, ingestion, or injection. See our Terms & RUO policy.