I don't know how effective Rogaine is for women, but for men it usually isn't effective at all. Very few men who use Rogaine see any improvement whatsoever. Any man who tries Rogaine to treat his hair loss should know that the likelyhood he will see any results whatsoever is very slim. There is however a new medication called Propecia which seems to be more effective at treating hair loss however, I believe it is for men only and has been known to have some undesireable sexual side effects.