Hi,
the length of time of vial of generic insulin depends on what your insulin dose is. For example. A
vial of insulin has 1000
Units. If you are taking say 50
units a day, then this vial will last for 20 days.
I used mixed insulin in the past, and while it can be quite effective, because it is a fixed amount of both medium and short acting insulin, you will need to eat on schedule to avoid going low.