Nutritive 8H Magic Night Hair Serum
An overnight leave-in serum designed to hydrate dry hair, soften frizz, and help hair feel smoother and more manageable by morning.
A strong overnight hair treatment for people with dry or frizz-prone hair who want softness and comfort without a heavy oil finish.
Most hair treatments are rinse-outs that stay on for 3–5 minutes at most. The 8H overnight premise is compelling — you are giving actives 8 hours to work rather than 5 minutes. For people with genuinely dry, frizzy hair who have not found rinse-out masks transformative enough, the format switch is a meaningful upgrade.
Last step of the evening haircare routine — after any scalp serum (like Genesis Serum Fortifiant), applied to mid-lengths and ends. Leave in overnight; no rinse.
People with dry, thick, coarse, or frizz-prone hair who want an easy nighttime routine that does some heavy lifting while they sleep. Also great for frequent heat-stylers or colour-treated hair that loses moisture quickly.
On very fine hair applied too generously. The overnight window allows more absorption than a quick rinse — fine hair types that oil quickly can wake up to flat, heavy-feeling hair if the amount is misjudged.
If hair starts feeling weighed down or waxy, reduce the amount used and focus application only on the driest inch of the ends. The formula may be too rich if hair already has product buildup.
- The Kérastase Nutritive shampoo and conditioner as the base of a coordinated dry-hair routine
- Used after the Genesis Serum Fortifiant on the scalp for a complete scalp-to-tip nighttime treatment
- The Ordinary Argan Oil as an optional extra drop mixed in for very dry or coarse hair ends
Best For
- Dry hair
- Frizzy hair
- Overnight repair support
- Softening rough hair
- Smoother morning styling
How to Use
Apply to dry or towel-dried lengths and ends before bed as a leave-in treatment. Avoid the roots. Leave in overnight and style as normal in the morning.
Key Ingredients
Draws moisture to the skin, helps maintain hydration, and reinforces the skin barrier.
Attracts and retains moisture, soothes irritated skin, supports barrier repair, and improves skin texture and softness.
Fragrance has no skincare function — it is added purely for sensory appeal and brand experience. Some fragrant ingredients (like linalool, limonene, and eugenol) are known sensitizers that can cause contact dermatitis in sensitive individuals over repeated exposure.
Ingredients to Note
May be a concern for some skin types. Tap to learn more.
Full Ingredient List
About This Product
The Kérastase Nutritive 8H Magic Night Hair Serum is a leave-in overnight treatment from the Nutritive line — Kérastase's range built specifically for dry, thirsting hair. The premise is simple and smart: instead of a rinse-out mask that delivers active ingredients for only a few minutes, the 8H format delivers a prolonged overnight hydration cycle. Applied to dry lengths before bed, the serum's conditioning complex has eight uninterrupted hours to soften, smooth, and reduce frizz before morning. The Nutritive line has always positioned itself around intense hydration for dryness-prone hair, and this serum extends that philosophy into a leave-in nighttime format that competes meaningfully with the growing category of overnight hair treatments. For people who travel, use heat tools regularly, or have chemically processed hair, this is a genuinely practical and effective step.