One coat at a time but I apply multiple coats per day around every 3-4 hours. When you apply it and work it in, it will become invisible but I can assure you that you have the barrier on with your lips being soft to touch. The next day you'll start to notice it. You shouldn't remove the barrier at all otherwise your new skin will die then peel and you'll have to restart all over again. As long as you keep the barrier on, the lips will heal each day but do not take it off. (You can actually see new skin forming underneath the barrier after only a few days) That was the mistake I made. I took it off when it wasn't ready. I learned the hard way.
But Longterm, why are you trying this when you don't need to heal your lips?