The posology on the bottle shall tell you for each of them
BEWARE though, at first it will cause die off (herxemeyer reaction), i.e. a lot of yeast will die and toxins will move about your body causing pain and headache and rashes. Sooooooo, if the posology says 3/day, you start with one a day and slowly increase over a few days and you will avoid the drastic die-off.