Encyclopedia entry

Peptide storage and handling

Most research peptides arrive lyophilised (freeze-dried) as a white powder under partial vacuum in a sealed glass vial. In this state, peptides are reasonably stable at room temperature for short transit and substantially more stable when refrigerated or frozen. Reconstituted solutions are far less stable than the lyophilised powder, and the handling of reconstituted material falls outside the scope of this editorial encyclopedia.

Why peptides ship lyophilised

Water is the main driver of peptide degradation. Freeze-drying removes the water and locks the peptide in a stable amorphous state. Lyophilised peptides typically survive 24 to 48 hours at ambient temperature with negligible degradation, which makes ordinary UK courier delivery practical. Without lyophilisation, peptides would require refrigerated transit and have far shorter shelf lives.

Lyophilised storage

• · Refrigerated (2 to 8°C): typically stable for 6 to 12 months for most peptides.
• · Frozen (minus 18°C or colder): often stable for 12 to 24 months.
• · Room temperature: stable for short periods (days to weeks), then progressive degradation.

Reconstituted material

Once a lyophilised peptide is dissolved in a solvent, its stability is far lower than the dry powder, because water is the main driver of peptide degradation. The practical handling of reconstituted solutions falls outside the scope of this editorial encyclopedia. PeptideClear covers the chemistry and the lyophilised storage characteristics only and does not publish handling steps.

Cold-chain for GLP-1 medications

Licensed GLP-1 medications (Wegovy, Mounjaro, Saxenda) are pre-filled pen injectors that ship under cold chain (2 to 8°C). Once in the user\'s fridge, they remain stable for the labelled shelf life. Once at room temperature, the manufacturer-specified out-of-fridge window differs by product (Mounjaro 21 days, Wegovy 28 days, Saxenda 30 days): typically 21 to 30 days depending on the product, and the Patient Information Leaflet (PIL) is the authoritative source. UK pharmacies dispensing GLP-1 maintain validated cold-chain logistics; this is one of the GPhC requirements.

Related: research peptides hub · UK pharmacies.