I had botox over a year ago for the same reason as you and to be honest I was quite disappointed with how long it lasted. About 3 months I'd say then my wrinkles came back the same (certainly not worse) than before. It's just expensive to keep it up, as much as I loved the initial results! But no, the lines aren't stronger than they were. The more often you go for sessions the less frequently you'll need to go for touch ups. I'm currently debating whether or not to carry on so to reap the long term benefits.