Botox comes as a frozen powder and must be reconstituted. There are differing opinions on what amount of diluent should be mixed with the powered botox. The botox powder comes in 50 unit and 100 unit vials. Some the of the accepted dilution amounts include 1cc per 100units, 2cc, 2.5cc, 3cc and 4cc per 100 units. Some European and South American physicians will use up to 6 cc per 100 units.
The argument for a more dilute botox reconstitution (4cc-6cc per 100 units) is more botox dispersion for a softer appearance, but there may be a higher incidence of dispersion related complications (such as lid droop). Those that use a more concentrated botox reconstitution technique (1-2cc per 100 units) claim less risk of dispersion, a more precise effects and longer duration, with fewer dispersion complications.
As always, the most important factor in any medical treatment is seeking out a very experienced physician who is very adept at their botox technique and approach.
Always consult with a specialist after online advice to see if you are a candidate for the procedures discussed.