Peptide Storage and Handling: Temperature, Light and Shelf Life
Peptides degrade through hydrolysis, oxidation and aggregation. Every storage rule exists to slow one of those three processes. Understanding which one you are fighting makes the rules easy to remember.
Lyophilised vials
In freeze-dried form, water is absent, so hydrolysis is effectively halted. This is why sealed lyophilised peptides are stable for years at -20 °C and tolerate weeks at room temperature during shipping without meaningful loss.
Keep sealed vials at -20 °C for long-term storage. Refrigeration is acceptable for shorter periods. The critical point is keeping the seal intact — moisture ingress is what ends shelf life.
Always allow a frozen vial to reach room temperature before opening. Opening a cold vial draws in humid air that condenses onto the powder.
Reconstituted solution
Once water is present, hydrolysis begins. Reconstituted peptides belong at 2-8 °C, and the usable window is weeks rather than months for most compounds.
Do not freeze reconstituted vials for repeated use. Each freeze-thaw cycle causes aggregation and measurable potency loss. If long-term storage of solution is unavoidable, aliquot into single-use portions first and freeze those once.
Light and oxidation
Peptides containing tryptophan, methionine, cysteine or tyrosine are the most light- and oxidation-sensitive. Copper complexes such as GHK-Cu are also strongly light-sensitive.
Store vials in their carton or in an opaque container. Minimise the time solution spends on an open bench under lighting.
Shipping in South Africa
Lyophilised peptides are routinely shipped at ambient temperature worldwide without cold chain, because the freeze-dried state is what protects them. Transit heat across South Africa is not a degradation concern for sealed vials.
Move vials to cold storage promptly on arrival, and inspect for a intact seal and a uniform white powder cake before accepting the batch.
Frequently asked questions
- Do peptides need to be shipped cold?
- Lyophilised peptides do not. In freeze-dried form they are stable at ambient temperature for the duration of normal courier transit, which is why cold-chain shipping is not standard for sealed research vials.
- Can reconstituted peptides be frozen?
- They can be frozen once if aliquoted into single-use portions, but repeated freeze-thaw cycles cause aggregation and potency loss. Routine storage of reconstituted solution should be at 2-8 °C.
- How long do lyophilised peptides last?
- Sealed lyophilised vials stored at -20 °C are typically stable for years. The limiting factor is seal integrity and moisture ingress, not time alone.
All information on this page is provided for laboratory and educational reference only. Peptides Lab SA (PTY) Ltd supplies compounds strictly for in-vitro research use. Nothing here is medical advice, a dosing recommendation, or a claim of human safety or efficacy.