Storage & handling
A correctly synthesised, independently tested peptide can still be ruined in a freezer. Every format PepcoLab supplies has its own requirement, and the vial and the pen of the same compound are opposites.
Looking for the science rather than our specifications? Storage conditions for research peptides covers how and why peptides degrade.
| Format | Unopened | After opening / reconstitution | Freezing |
|---|---|---|---|
| Lyophilised vial | −20 °C, desiccated, protected from light | 2–8 °C once reconstituted, use within 28 days | Frozen is correct while lyophilised. Avoid repeated freeze–thaw once in solution. |
| Pre-filled pen | 2–8 °C, do not freeze, protected from light | 2–8 °C, discard 28 days after first use | Never freeze. A pen is supplied in solution and freezing it is not recoverable. |
| Nasal spray | 2–8 °C, do not freeze, protected from light | 2–8 °C, discard 28 days after first use | Never freeze. |
| Bacteriostatic water | Room temperature, away from direct sunlight | Room temperature, sealed between uses | Do not freeze. The bacteriostatic preservative is what permits multiple entries. |
| Acetic acid solution | Room temperature, away from direct sunlight | Room temperature, keep sealed | Do not freeze. |
Where a specific compound carries a requirement of its own, it is stated on that product's page and on the documentation supplied with the order. That always takes precedence over this table.
The three mistakes that ruin material
Freezing a solution
Pens and sprays arrive in solution. Freezing risks aggregation, and thawing does not undo it. The vial and the pen of the same compound have opposite requirements.
Repeated freeze–thaw
Every cycle degrades material in solution a little further. Aliquot at reconstitution rather than returning one vial to the freezer repeatedly.
Ignoring the 28 days
The in-use window for reconstituted material at 2–8 °C is a limit, not a target. Plan the work around it rather than discovering it afterwards.
Common questions
Why −20 °C for vials but 2–8 °C for pens?
They are physically different materials. A lyophilised vial contains dry powder, which is most stable frozen and desiccated. A pen contains material already in solution — freezing a solution risks aggregation and cannot be reversed by thawing it.
Where does the 28-day figure come from?
It is the documented in-use window for reconstituted material held at 2–8 °C, and it is what is printed on the documentation supplied with every order. Treat it as a limit rather than a target.
My parcel arrived warm. Is it ruined?
Not necessarily. Lyophilised peptides are stable for the transit window under the temperature-controlled packing used for dispatch — the dry state is considerably more tolerant than material in solution. If a shipment arrives visibly compromised, photograph the packaging and the product and contact us within 48 hours; that is the window for a refund or replacement.
Does repeated freeze–thaw matter?
Yes, and it is one of the commonest handling errors. Each cycle is an opportunity for aggregation and degradation in solution. Aliquot at reconstitution if the preparation will be drawn from repeatedly, rather than returning the same vial to the freezer.
Does light exposure actually matter?
For some materials, considerably. Copper complexes such as GHK-Cu and AHK-Cu are light- and oxidation-sensitive, which is why they are supplied and stored protected from light. Where a compound has a specific requirement it is stated on its own documentation.
What about the postal or courier delay?
Handling requirements begin when the parcel is opened. Material in transit is packed for that transit; requirements on this page apply to storage in your own facility once it arrives.
All materials are supplied for in-vitro laboratory research use only. Nothing on this page describes preparation for human or veterinary use, and PepcoLab does not provide dosing, administration or protocol guidance.