Does a Vial of Botox Come Pre-mixed?

Botox does not come pre-mixed. Botox comes in a powder form and is shipped in a small glass vial. It is then mixed with Saline before use. It does not have to be mixed each time it is used, but 100 Botox units are mixed at a time.
Our patients normally have between 20 units and 60 units injected so in many cases a portion of the vial remains for the subsequent patients.

Botox is stored in a cold environment and has no liquid in it when the manufacturer delivers it.
We generally use a minimal dilution as I think more concentrated Botox allows us to use fewer needle sticks.  Others dilute it more, but my concern is that higher dilutions may not last as long.

It is mixed every time it is first opened. The same bottle has enough units of Botox to treat two to three cosmetic units. This rarely is all done on the same patient, and more commonly provides doses for two or three patients.

Botox does not come premixed. It comes freeze dried (kinda like astronaut food). The injector will help pick the dilution of botox depending on the intended application. Once botox is mixed it should ideally be used within 4 hours of reconstitution but this number is controversial. Botox can be made more dilute but can never be made more concentrated (Add saline to product but do not add actually botox to reconstitution).

Botox does not come pre-mixed and needs to be reconstituted with normal saline prior to injection. Once mixed, the effectiveness of Botox can last for a certain period of time. Everyone dilutes their Botox with different amounts of normal saline, thus you should know how many 'units' of Botox that you are receiving and not how many 'cc's'. Good luck.