Setup, so nobody has to ask: 2–8 °C · cagrilintide.
This is asserted often enough that I assumed it was established, and then I went looking for the source.
I have searched the primary literature and found one paper that is adjacent but not on point.
Has anyone verified this independently?
2–8 °C is inside or near the refrigerated band. 2–8 °C is the condition the rule of thumb is anchored to, so it is the baseline rather than a multiplier: everything else in this thread is quoted relative to it. That is the condition most lyophilised peptide is specified at, so the useful question moves to what happens after reconstitution, where the same temperature buys far less. Nothing here is medical advice, and research-use-only material is not approved for human use.
On the detail: this is the tag where the advice is cheapest to follow and most often ignored.
Store with the desiccant sachet if one was supplied, inside the secondary container rather than loose in a drawer. Residual moisture is the dominant variable in solid-state stability.
Lyophilised powder: refrigerated at two to eight degrees for months, frozen at minus twenty for longer. The gain from minus eighty over minus twenty is small for a dry solid and is not usually worth the arrangement.
Residual moisture is the dominant determinant of solid-state stability, which is why desiccants accompany lyophilised material.
Keep the desiccant with the vial and the certificate with the lot code.
Aggregated, published test results and vendor ratings built from submitted batches. Methodology stated, dataset browsable, no listing fees.
Browse resultsIt helps to be literal here: desiccant matters more than the last few degrees of cold for a lyophilised powder.
Reconstituted with a preservative-containing diluent: refrigerated, conventionally treated as usable for about 28 days from first entry. Without a preservative, single use and discard.
Position matters less than people think: upright or on its side makes no difference to a lyophilised powder, and upright is marginally better for a reconstituted vial because it keeps the stopper dry.
Photodegradation of tryptophan-containing peptides is documented and is the basis for light-protected storage recommendations.
Nothing here is medical advice, and research-use compounds are not approved for human use.
Label the vial at reconstitution with date, concentration and units per dose.
Keep the paperwork with the material, or the material becomes anonymous.
Let a refrigerated or frozen vial equilibrate to room temperature before opening, so humid air does not condense water onto a cold cake.
Keep the certificate with the vial, physically or as a photograph filed under the lot code. A vial without a traceable certificate is an anonymous vial regardless of where it came from.
The caveat is that storage conditions preserve what you have and cannot improve it.
Minus eighty buys very little over minus twenty for a dry solid.
edited 20 Dec 2025 by h_pergande — added a caveat about sampling
Answer first: dry, cold, dark and still, with the lot code where you can still read it in a year.
Keep vials in their original carton or in an opaque box. Light exposure matters for tryptophan-containing sequences and for anything with a chromophore, and a closed box is free.
The 28-day in-use period for preservative-containing multi-dose preparations is printed on the diluent labelling and is a long-standing pharmacy convention.
Dry, cold, dark, still. Four words and you have the answer.
Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.