anywhere the skin needs to develop i will expect overgrowth, i think that's how it works but it needs natural moisture(urea). I haven't had any overgrowth in a while since the first 4 days. I'm on day 16 i think. When i wake up it's still normal. When i eat cereal, normal. Drink water normal. I am still cautious with my lips not to cause damage. I want to go 2 months, i know as long as i use it i won't have a problem doing that.