Hair Longevity Treatment. The super serum - clinically proven results: More hair density: 84% 1 Thicker looking hair: 76% 2 In just one month: thicker, fuller-looking hair that feels revitalized from the root. 1 Percentage of subjects showing an increase in hair density after a 3-month treatment course (trichoscan analysis on 55 men and women volunteers)2 Satisfaction test on 55 panelists after 3 months of use. | Sisley Paris Revitalizing Fortifying Super Serum Advanced Formula, 60 ml | Dermstore