Skip rogaine,
go for propecia, it is the best thing for *maintaining* hair. Wont grow back that much. But then neither will Rogaine.
I tried rogaine for more than a year. Rogaine is minoxodil 2-5% suspended in an alcohol solution.
Because you have to put it on in the morning and at night, and the fact that you are in essence putting alchohol on your scalp and hair, your scalp and hair will suffer alot of drying.
I dubbed rogaine "Bad hair in a bottle", because of the drying effect. Propecia works as well if not better, and you take it orally.
No known side effects with Rogaine. Side effects for propecia are "No Captain Happy Pants For You". But that is only in 2% of the cases.