S.N.
I've had it done 4-5 times for the lines between my eyebrows (I have those horrible 11 lines there!).
I would continue to do it to maintain them disappearing BUT I'm unfortunately one of the .000001% of people that Botox does not really work on! so instead of them being gone for 3-6 months.... they come back in 6-8 weeks and at almost $400 a session (per area).... I can't afford that (nor do I think I would want that much poison going in me!!).
All that aside I would try it and see if it works for you. I've never had my forehead done... I could see where that would make you look a little frozen... but as one poster says after a few days or so it loosens up. try it on a Friday and see what happens.
Whatever you do go to a DR. office.... and try and have a plastic surgeon do it. I've had a DR and a lady who was just trained... the Dr. was the same cost and I got a better result.