Wake up to stronger, smoother, fuller and more youthful-looking hair. ✨

Transform your hair while you sleep with Kérastase Chronologiste Overnight Youth Serum, a luxurious age-corrective leave-in treatment designed to combat the 5 visible signs of hair ageing.

Infused with Pro-Xylane™ and Ochrophyta Algae, this advanced overnight formula deeply hydrates, strengthens and smooths ageing hair while restoring body, softness and radiant shine from root to tip.

Its lightweight, nourishing formula works overnight to reduce frizz, improve hair strength and enhance fullness, leaving your hair looking beautifully revitalised by morning. With added heat protection of up to 232°C (450°F), your hair stays protected during heat styling.

Key Benefits:

✨ +92% Hair Strength – Helps strengthen and protect weakened hair
✨ -66% Frizz – Smooths unruly strands for a sleeker finish
✨ +32% Shine – Enhances hair's natural radiance
✨ +5.7% Hair Fibre Diameter – Promotes fuller, thicker-looking hair
✨ Deep Hydration – Replenishes moisture and improves softness
✨ Heat Protection up to 232°C – Helps protect hair from heat-styling damage

Key Ingredients:

• Pro-Xylane™: An advanced anti-ageing molecule that helps strengthen and protect hair.
• Ochrophyta Algae: Bio-sourced deep-sea algae known for its regenerative and revitalising properties.

How to Use:

1. Apply one pump to dry or damp hair before bedtime.
2. Distribute evenly throughout the mid-lengths and ends.
3. Leave in overnight. No rinsing required in the morning.

For Best Results: Pair with the Kérastase Chronologiste Bain and Masque for a complete age-defying haircare ritual.

Indulge in luxurious overnight haircare and awaken to beautifully smooth, stronger and healthier-looking hair every morning.

Performance percentages are based on instrumental testing after one use of Overnight Youth Serum. Full-system results are based on using Chronologiste Bain, Masque and Overnight Youth Serum together.