-->i was wondering how long does PROACTIVE SOLUTION<--

Hi
I have seen all the infomercials of Proactive Solution and i'm pretty much near trying it out! I was wondering if i have to use proactive the rest of my life to stop my Acne problems or just a certain ammount of it will clear me from my skin problems like the accutane pills for example!?! I'm seeing my dermatologist soon and i'm hesitating on the proactive solution because i dont know if it's going to clear me from my Acne problems for the rest of my life like my dermatologist can! I mean i'd rather pay 500$ and have Acne free skin then pay 40$ every 2 months for the rest of my life. I just want to know how long does Proactive solution work? Does it only work when you use it?
Thanks! =)