The New Chronologiste range offers youth-revitalizing care for hair longevity, not only by reducing visible signs of aging but also rebooting weakend hair to optimize hair health. The New Chronologiste has a targeted regimen to visibly improve five key signs of hair aging: frizz, dryness, dullness, lack of thickness, and lack of volume.The secret is the combination of two powerful ingredients:Pro-Xylane in serum: A renowned age-supporting ingredient that is renowed for renewing tissue from scalp to fiber, stimualting hair activity to increase hair shaft diameter and thickness. It also restores scalp hydration and elasticity, fostering healthy hair activity.Ochrophyta Algae in bain and masque: A bio-sourced deep sea extract that enhances skin barrier integrity, improves hydration, moisturizes, prevents split ends, and boosts shine and elasticity by binding with hair proteins.The Restorative Night Serum is optimized for nighttime application to maximize its efficacy. Drawing inspiration from skincare principles, this allows active ingredients an extended period to penetrate and act, minimizing interference from daytime environmental aggressors. This approach leverages the body's natural nocturnal restorative phase, optimizing absorption for enhanced hair health and manageability upon waking, while also providing a moment of self-care.Benefits after one night*: • Increases fiber diameter by 5,7% • 66% less frizz*• 32% shinier hair* • 92% more strength*• After the routine 77% say their hair feels revitalized***Instrumental test after one use of the Overnight serum **Consumer test on 90 women after one application of the full Chronologiste routine (bain, masque + Overnight serum) How to Use: Apply on dry or damp hair before bedtime. Spread one pump into hands and distribute on lengths and ends. No need to rinse in the morning. Kérastase Chronologiste Overnight Youth Serum 90 ml