The Science of Oily Roots and Dry Ends Oil produced from the scalp can build up causing the roots to become visibly greasy, weighing down the hair. Over-washing to combat this problem can strip the fibre leaving it dry. This results in a vicious cycle of washing. What if you could have hair that was cared for at both ends? The Secret of Clay for 72 Hours of Pure Roots and Hydrated Ends For the first time, L'Oral Paris Laboratories have combined 3 Refined Clays to create its first re-balancing range revealing perfectly balanced, beautiful hair.