Bosley Defence Thickening Treatment for Non Color-Treated Hair What it is: Leave in intensive treatment. What it does: Creates thicker feeling hair while helping to inhibit the action of DHT, protect and repair hair follicles and help support healthy hair function. How to use it: Apply daily to scalp and hair, do not rinse. * Features & Benefits LifeXtend Complex - Hydrates and nourishes while strengthening and fortifying the follicles and hair shaft for thicker, fuller looking hair. Kelp Extract - Helps protect from photo aging, frequent washing and damage due to brushing. Sage Leaf Extract - Helps stimulate healthy hair growth.