WHAT IS IT?

Overnight Youth Serum by Kérastase is an age-corrective night treatment infused with Pro-Xylane™ and Ochrophyta Algae, designed to reverse the visible signs of aging during nighttime.

Targeting dryness, dullness, frizz, lack of volume and thickness, this leave-in serum delivers intensive overnight care. Just one pump to deliver powerful actives deep into the hair.

Powered by Pro-Xylane™, a green chemistry molecule known for its ultimate anti-aging action, and Ochrophyta Algae, the fastest growing algae in the world, a bio-sourced deep sea treasure that captures the regenerative power of the ocean. 

Its transformative quick-break texture melds instantly into the hair's lengths, leaving a perfect finish and enveloping hair with the signature Chronologiste fragrance that turns routine care into a luxurious ritual.

Apply to dry or damp hair before bedtime. Spread one pump into hands and distribute evenly through lengths and ends. No need to rinse.

Wake up to fuller, healthier, smoother hair.

HAIR BENEFITS AFTER 1 NIGHT
Increases fiber diameter by +5.7%*
-66% frizz*
+32% shine*
+92% more strength *
77% say their hair feels revitalized**
*Instrumental test after 1 use of Overnight Youth Serum
**Consumer test after one application of full Chronologiste routine, bain+masque+Overnight serum

WHO IS IT FOR?
For hair weakened by signs of aging: lack of thickness, frizz, dullness, dryness, lack of volume.

BUSINESS OPPORTUNITY

Since 1900, the average lifespan has doubled. Women today are not the women of yesterday; they are liberated, audacious, and actively striving to live better. For these women, confidence is essential, and their hair plays a vital role in expressing their individuality and feeling of youthfulness. Yet, like skin, hair also succumbs to the aging process.

After decades of dedicated scientific research, L'Oréal has successfully decoded the complex science behind hair aging. KÉRASTASE identified five key signs of aging hair: dryness, dullness, frizz, loss of volume and thickness.

To visibly counteract these concerns, KÉRASTASE presents Chronologiste: an advanced routine that applies cutting-edge skincare science directly to haircare. This transformative approach delivers immediate results, revealing visibly fuller, smoother, and healthier hair in just one night.

Step 1: Apply on dry or damp hair before bedtime. Spread one pump into hands and distribute on lengths and ends.

Step 2: No need to rinse in the morning.

In case of direct contact with eyes, rinse immediately and thoroughly.

1. Do I need to rinse it out in the morning?
No. The formula is designed to be leave-in and absorbs fully overnight with no residue.

2. Can I use it on both wet and dry hair?
Yes. It can be applied to dry or towel-dried hair as the final step of your evening routine.

3. Will it make my pillow greasy or sticky?
No. The quick-break texture absorbs instantly, leaving no residue on fabric or hair surface.

4. What is the scent of this serum?
Chronologiste owns a luxurious couture scent, a floral and sensual fragrance.

5. What are the benefits of this serum?
It reverses 5 signs of hair aging in 1 night and reveals fuller, healthier and smoother hair.