Temperature is the primary driver of peptide degradation. From the moment a batch leaves the manufacturer to the moment you reconstitute it at the bench, maintaining the cold chain protects the purity you paid for. Here is how to think about it at each stage.
Why cold matters
The chemical reactions that break peptides down — hydrolysis, oxidation, aggregation — all accelerate with heat. Cold storage slows them to a crawl. A lyophilized peptide is far more tolerant of brief temperature excursions than one in solution, but cold and dark remain the goal at every stage.
In transit
Temperature-sensitive compounds ship with appropriate cold-chain materials such as insulated packaging and cold packs. Short exposure to ambient temperature during shipping is generally well tolerated by lyophilized powder, which is one of the practical advantages of the freeze-dried form. On arrival, inspect the vial and move it to cold storage promptly.
Lyophilized storage
- Store sealed vials of powder at -20°C, protected from light and moisture.
- For long-term storage, -80°C offers an additional margin for many compounds.
- Keep vials in a sealed container with desiccant to guard against humidity.
After reconstitution
Adding diluent restarts the degradation clock. Reconstituted peptide should be kept refrigerated at 2–8°C for short-term use. For anything longer, divide the solution into single-use aliquots and freeze them. This is the most important habit in peptide handling, because it avoids the real enemy of stability: repeated freeze-thaw cycles.
The freeze-thaw problem
Each time a solution freezes and thaws, ice-crystal formation and shifting concentration stress the molecule. A vial thawed and refrozen a dozen times will lose integrity far faster than one thawed once. Aliquoting up front means you only ever thaw what you need, exactly once — the simplest, highest-impact step you can take to keep a compound at its certified purity.
