I've had it for about 18 months and I've been leaving it alone for about 6 and 1/2 months. The grooves are very important in my opinion, but probably more noticeable on the bottom lip (I think it takes longer to heal). When the dead skin comes off (either on its own or if you take it off for whatever reason) you'll probably initially notice that the skin under it is RED and doesn't really have grooves. Of course, you'll always have the grooves at the bottom of the lip which are prominent when you curl your lips, but What you WANT is for your lips to go back to their natural color (a palish pink rather than red) and for the grooves to come back within the afflicted area. This means that the layer underneath is strong enough to stop peeling. Try to leave the "scab" on as long as possible. And yes, the lips turn yellow during the peeling process, but that's what you want. This is the way to heal. I'm almost there. I'll post about it when I'm 100% (not 90 not 65) cured. Good luck!