Botox is a great medication to use to prevent wrinkles from forming or to help reverse the signs of aging.  When I see a client for the first time for Botox, I generally like to start off on the more conservative end of treatment.  I always stress that you can add more, but you can never take it out.  Botox will typically last you 3-4 months.  When doing Botox for preventative actions, I suggest having injections every 6-12 months.  For women who want to turn back time, every 3-4 months is going to be a good amount of time.  If Botox is not lasting at least 3 months, the person injecting it may be using a small amount or have poor technique.  Sometimes Botox can be over diluted (watered down) which will require more units to effectively work and will end up costing you more money.