Peptide oxidation and deamidation — storage condition impact

PeptideChemSF said:

The distinction that matters is unopened versus in use.

Cold chain shipping for storage and cold: my last order arrived with the cold pack completely melted and the vial at room temperature. I contacted the vendor and they reshipped with better insulation.

What to look for in shipping: gel ice packs + insulated liner. If your peptide arrives warm, contact the vendor immediately. Don't assume it's still good.

One thing that is still open after Dr.PulmRoch’s answer:

Did your prescriber agree with that reading, and if not what was their objection?

dave_SLC said:

Cold chain shipping for storage and cold: my last order arrived with the cold pack completely melted and the vial at room temperature.

Coming at dave_SLC’s question from a different direction. Worth answering the question that was asked rather than the one behind it. The narrow version usually has an answer; the broad version usually does not, and answering the broad one is how a thread stops being useful.

OP back with an update, since a thread like this is useless without one.

Follow-up — I binned the frozen one. Aggregation does not undo itself and I was not going to inject a maybe.

andrew_nyc said:

Worth answering the question that was asked rather than the one behind it.

True, with the qualification that this is a self-selected group. The people for whom it did not work post less, and that shapes everything we think we know.