WHAT IS IT?

Kérastase Sérum Nuit Jeunesse is an age-correcting overnight treatment infused with Pro-Xylane™ and Ochrophyta algae, designed to visibly reverse the signs of hair aging while you sleep.

Targeting dryness, dullness, frizz, and loss of volume and thickness, this leave-in serum delivers an intensive nighttime treatment. One simple gesture is enough to diffuse powerful active ingredients deep into the hair fiber.

Its formula combines Pro-Xylane™, a green-chemistry molecule renowned for its exceptional anti-aging properties, with Ochrophyta algae—the fastest-growing algae in the world. This biosourced marine treasure captures the regenerative power of the ocean.

With its transformative “quick-break” texture, the serum instantly melts into the lengths, leaving a flawless finish while enveloping the hair in the iconic Chronologiste fragrance. The result is a luxurious nighttime ritual that elevates hair care into a sensorial experience.

How to use

Apply to dry or towel-dried hair before bedtime. Dispense one pump into the hands and distribute evenly through lengths and ends. Do not rinse.

Wake up to hair that feels denser, healthier, and softer.

BENEFITS FROM THE FIRST NIGHT

• +5.7% increase in hair fiber diameter**
• -66% frizz*
• +32% shine*
• Hair is 92% stronger*
• 77% of women report hair feels revitalized**

*Instrumental test after one application of Sérum Nuit Jeunesse

**Consumer test on 90 women after one use of the Chronologiste routine (bath + mask + night serum)

WHO IS IT FOR?

Ideal for hair weakened by the effects of time: dryness, dullness, frizz, and loss of volume and density.

HAIR LONGEVITY

Since 1900, life expectancy has doubled. Today’s women are bold, empowered, and driven by the pursuit of a better life. Confidence plays a vital role, and hair is a key expression of individuality and youthfulness. Yet, like skin, hair is subject to the aging process.

After decades of advanced scientific research, L’Oréal decoded the complex science of hair aging. Kérastase identified five key signs of mature hair: dryness, dullness, frizz, loss of volume, and loss of density.

To visibly reduce these signs, Kérastase created Chronologiste—an expert routine that translates skincare science directly into haircare. This transformative approach delivers immediate results, revealing hair that looks denser, smoother, and healthier from the very first night.