The time is a factor of certain things:
1. The size of the treated area – the bigger area – the longer time it will require
2. The color of the skin and the hair – the lighter will consume more time to accomplish
3. The hair type – the thinner and fine hair you have – the more time it will take to accomplish the task
4. The machine type – there are machine that will do the job in a shorter period of time.
A typical session for the upper lip should not last more than 10 minutes.