Hi Shirley,
This is a great question and important consideration. For Salvia officinalis, you can take up to 2 g/day (if you put 0.5 g per capsule then this would be 1 cap 2-4x/day) for 2-3 months or so, then swap it out for another herb for a few months and reintroduce it again.
I would suggest starting on the lower end of the range and working up over the course of the first week if you need to.
Warmly,
Benna