I found reply from guys describing themselves as peptide vendors on different forums on atleast two occasions saying that peptides, even ghrp+ghrh shouldnt be mixed due to different PH. It wasnt clear if it was for longterm mixing (aka overnight in needle) or just before applying,
Anecdotals from users usually says they mix to lower pinning amount and they still get "results" when it comes to ghrh+ghrp combo. Though they usually do air bubble space between ghrh + ghrp.
So if you dont wanna take chances with ruining or lowering effect you shouldnt mix at all. If you do, dont store it mixed and make air bubble between peptides in syringe.
Definetely dont mix igf with others.
Storage time is same as reconstitued peptide in vials. Stored in dark and cold enviroment atleast weeks, propably up to 6 months.