Research question
Do light and heat matter for the dry vial?
Peptides in a dry cake are more stable than the same peptide in solution, but they are not indifferent to storage. GetReta’s direction is refrigeration at 2 to 8 °C, protected from light, for the sealed vial. A sunny windowsill, a car in summer, or a fridge that is actually a warm cupboard are not that direction. Light protection can be the carton itself, or an amber box in the laboratory fridge, as long as the lot label remains readable.
Do not assume that a short warm spell is fine because the certificate quoted a high HPLC purity. That purity was measured on the retained sample under the conditions of the test, not after a week in a post room you do not control. Once you have the parcel, the storage is yours.
GetReta does not publish a corrective step for a vial that was overheated. Email the lot and the order reference and describe how it was kept. Research use only.