I stopped biting my lips when I was 21 and I'm 31 now and I have seen some improvement.
If you look at the gallery might lips looked like kartis after a week but now they dont look anywhere near that even after 3 weeks but they are still bad.
I've only had a really good diet though in the last year and that has seen the best improvement, miles from being cured though, to be honest I would make do with manageble so I can kiss someone!, its beenb a long time!