21+ · VERIFIED LAB USE
Contact
Storage temperatures, light and moisture protection, freeze-thaw damage and shipping considerations for lyophilized research peptides.
Sealed lyophilized peptide is held at -20 C, desiccated. At that temperature most sequences are stable for well over a year. Refrigeration at 2-8 C is acceptable for shorter periods; room temperature storage is for shipping windows, not for holding stock.
Desiccation matters as much as temperature. A freezer is a low-humidity environment only while the door stays shut; repeated opening cycles moisture through it.
Sequences containing tryptophan, tyrosine or a conjugated ring system degrade on light exposure. In this catalogue that means GHK-Cu, Hexarelin, DSIP, MOTS-c, PT-141 and Melanotan II in particular.
Opaque secondary packaging handles storage. During handling, the working time on the bench is short enough that ambient room light is not usually a problem, but leaving a reconstituted vial under a bench lamp is.
Some compounds pull water from the air aggressively. NAD+ is the extreme case in this catalogue. Bringing the vial to room temperature before opening is the single most important handling step for these.
Once moisture is in the vial it will not be removed by returning it to the freezer.
Each freeze-thaw cycle damages peptide in solution. Ice crystal formation concentrates solutes at the boundary and can drive aggregation.
If a reconstituted solution will be used across multiple sessions, aliquot it into single-use portions at the point of preparation rather than repeatedly thawing one stock vial.
Methionine and cysteine are the two residues to watch. Methionine oxidises to the sulfoxide, adding 16 to the observed mass; cysteine forms disulfides.
Sequences with free thiols - L-Glutathione most obviously - should be kept tightly sealed and their solutions prepared immediately before use.
Lyophilized peptide tolerates ambient shipping for the length of a domestic transit. It ships insulated with phase-change packs to hold the parcel below room temperature and to buffer against a hot delivery vehicle.
Material arriving warm is not automatically compromised - the lyophilized form is robust over short windows - but it should go into -20 C storage promptly on receipt.
This guide is general laboratory reference material relating to the handling of research compounds. It is not medical, veterinary or clinical guidance, and it does not describe or imply any use in humans or animals. All PeptideSeed material is supplied for in-vitro laboratory research only — see the terms of supply.