Yes, I know that Botox has about a 90% success rate. Yay!
I haven't read that most people get it right the first time.
I guess I was in part thinking of people who post on this board; and also in terms of the current question that was presented—about perhaps trying Botox ONCE before going to visit parents.
It might work, it might not.
"A number of sessions" meaning maybe a year for some, or a few months, with, occasionally (with a cooperative doctor), some going back for additional, or top-ups, after a few weeks at the beginning.
I wouldn't necessarily emphasize this as a "struggle," just that often it takes time.
And certainly taking time to get it right must be contributed to by the inclination of many doctors to start at a low dosage and work up.