I have been getting my forehead injected for about 3 years now. What a difference. Recently I started getting just a little around my eyes. Not only do the wrinkles relax when the Botox kicks in, but if you get them regularly you will have LESS wrinkles than you did before, even if you stop getting the injections. It's like ironing a shirt and not wearing it.
I'm in my forties and I feel that getting just a moderate amount will go a long way to prevent further wrinkles from developing. In my experience, the effects last just about 4 months. I wish it lasted longer, but if you want to keep it up it is something you need to do 3x a year.
The injections in the forhead and brow don't hurt at all. The area under the eye does hurt a little but it goes away very quickly. Arnica prevents bruising if you use it right away, and there isn't any swelling.