Degradation modes
Oxidation (methionine, cysteine, tryptophan side chains), hydrolysis (peptide bond cleavage in aqueous solution), aggregation (intermolecular contacts especially in hydrophobic peptides), and adsorption to glass or plastic surfaces.
Drivers of stability
Lower temperature, lower pH variability, absence of light, absence of oxygen, and absence of repeated mechanical stress (shaking, freeze/thaw) all extend usable shelf-life.
Shelf-life rules of thumb
Lyophilised at -20°C: 24+ months. Reconstituted at 2–8°C: 4–8 weeks for most peptides. Refer to the COA's stability section for compound-specific data.
Frequently asked questions
Does refrigerated lyophilised peptide degrade quickly?+
Not significantly for several months for most peptides — but -20°C is safer for long-term storage.