KÉRASTASE Chronologiste Overnight Youth Serum 90ml — leave-in night serum with Hyaluronic Acid & Pro‑Xylane for hydration and shin

KÉRASTASE Chronologiste Overnight Youth Serum is a leave-in night treatment that hydrates, reduces frizz and restores shine while you sleep.

This lightweight overnight serum combines Pro‑Xylane™, Hyaluronic Acid, Abyssine and Ochrophyta Algae to target visible signs of aging hair: dryness, loss of radiance and weakened fiber. Designed to be applied to dry or damp hair and left in overnight, the formula works without rinsing so you wake up with softer, sleeker-looking hair and improved manageability.

How does this serum work while I sleep?

The Chronologiste Overnight Youth Serum delivers moisture and active repairing molecules in a leave-in texture so ingredients can act continuously overnight. Its small-molecule humectants keep the hair surface hydrated while reparative ingredients support fiber resilience and surface smoothness.

• Deep-hydrating hyaluronic acid helps retain moisture along the hair shaft.
• Pro‑Xylane™ targets structure to improve strength and bounce.
• Abyssine calms and protects the scalp environment for overnight recovery.
• Ochrophyta Algae smooths surface fibers to reduce frizz and increase shine.

How quickly will I see results and what can I expect after one use?

Visible improvements are reported after a single application: the formula reduces frizz, boosts surface shine and supports stronger-feeling hair from the first night. Results accumulate with continued use, improving manageability and overall appearance.

• Up to 66% less visible frizz after one application (brand testing).*
• Noticeably more shine—brand data cites a 32% increase in surface gloss.*
• Strength improvement reported in trials—brand data indicates up to 92% stronger hair.*
• Lightweight finish that won’t weigh hair down by morning.

How should I use the Chronologiste Overnight Youth Serum for best results?

Apply a small, even amount to lengths and ends of dry or towel-dried hair before bed; there's no need to rinse. For thicker or longer hair, distribute in sections and avoid the roots if you prefer non-greasy volume.

• Use a pea-to-dime sized amount depending on hair length and texture.
• Apply primarily to mid-lengths and ends to target dryness and breakage.
• Comb or finger-comb through to ensure even coverage before sleeping.
• Can be used nightly or as a restorative overnight boost when hair feels fragile.

Will this serum suit my hair type and styling routine?

The formula is built for aging, dry or chemically treated hair in need of hydration, shine and strengthened fiber. Its lightweight, leave-in nature integrates easily into most routines and complements daytime styling products without heavy buildup.

• Suitable for dry, brittle or chemically processed hair seeking overnight repair.
• Light enough for fine hair when used sparingly on lengths and ends.
• Works well with color-treated hair to restore radiance and reduce frizz.
• Pairs with daytime serums, oils or thermal protectors for styling needs.

Who is this for: KÉRASTASE Chronologiste Overnight Youth Serum is aimed at anyone noticing loss of shine, increased frizz or weakened hair fiber—especially mature, dry or color-treated hair types. If you want a hassle-free, leave-in night treatment that supports hydration, surface smoothness and a more resilient feel by morning, this serum is formulated to fit into your nighttime routine.

*Percentages cited are from brand consumer testing and internal instrument measures; individual results may vary.

Ingredients

AQUA / WATER / EAU • DIMETHICONE • GLYCERIN • ISOPROPYL MYRISTATE • PHENOXYETHANOL • POLYACRYLAMIDE • C13-14 ISOALKANE • LAURETH-7 • BENZYL SALICYLATE • HEXYL CINNAMAL • BENZYL ALCOHOL • LINALOOL • TETRAMETHYL ACETYLOCTAHYDRONAPHTHALENES • CARVONE • CITRUS AURANTIUM PEEL OIL • LIMONENE • POGOSTEMON CABLIN OIL • CITRONELLOL • LINALYL ACETATE • GERANIOL • HYDROXYCITRONELLAL • MACROCYSTIS PYRIFERA EXTRACT / KELP EXTRACT • HYDROXYPROPYL TETRAHYDROPYRANTRIOL • BENZALDEHYDE • GERANYL ACETATE • COUMARIN • CITRIC ACID • TRIMETHYLBENZENEPROPANOL • ROSE KETONES • PROPYLENE GLYCOL • BETA-CARYOPHYLLENE • POTASSIUM SORBATE • SODIUM BENZOATE • PARFUM / FRAGRANCE