Most of us are all too familiar with that “dreaded” internal clock that wakes us at 7:00 AM on the weekend, despite our desire to sleep in. We fail to appreciate that this internal clock is part of a natural body rhythm that can dramatically impact our skin.Scientific studies have revealed that our skin’s biological functions follow “circadian cycles” which vary over the course of a 24 hour period. In the skin’s biological clock, epidermal cell renewal and the permeability of the skin are bot.