Kérastase hair oil and serum are not interchangeable names for one product. Elixir Ultime is a finishing and conditioning oil for the lengths; Nutritive 8H Magic Night Serum is an overnight leave-in for dry hair; Genesis Serum Anti-Chute Fortifiant is applied to the scalp. Choose by the job you want the product to do and where it belongs.
Choose by your main concern
- Shine, softness and a smoother finish: look at Elixir Ultime L’Huile Originale.
- Dry lengths that need overnight care: consider Nutritive 8H Magic Night Serum.
- A scalp step for hair prone to breakage-related hair fall: explore Genesis Serum Anti-Chute Fortifiant.
What does Kérastase Elixir Ultime hair oil do?
Elixir Ultime is useful when the missing step is a polished finish. Work a small amount through the mid-lengths and ends, spreading it between your hands first. It can be used on damp hair before styling or sparingly on dry hair for touch-ups; follow the quantity guidance on your bottle.
Fine hair usually needs a lighter hand than thick lengths. Begin with less, check how the hair feels, then add only where needed. Applying a generous amount near the roots can leave a result that feels heavier than you intended. Hair oil does not replace shampoo or rinse-out conditioner.
When does an overnight serum make more sense?
8H Magic Night Serum suits a different moment in the day. It is a leave-in step for the lengths and ends before bed, on dry or towel-dried hair. You do not rinse it out in the morning. This makes it a practical option when you prefer to care for dry lengths overnight rather than add several products during styling.
It is not the same as putting a wash-out hair mask on overnight. Check the exact product name and instructions before changing the contact time of any treatment.
Where does Genesis scalp serum fit?
Genesis Serum Anti-Chute Fortifiant belongs on the scalp, not just on the tips. Its role is different from adding shine with an oil. For the application steps and the distinction between breakage and hair loss, read our Genesis serum guide.
A cosmetic serum is not a diagnosis or treatment for unexplained hair loss. Sudden shedding, patchy loss or an inflamed scalp calls for professional advice rather than simply adding another styling product.
Can you use more than one?
You can have different needs at the scalp and ends, but that does not mean you need all three bottles. Start with the concern you notice most. If you add a second product, give it a clear role and avoid repeatedly coating the same section of hair.
Is hair oil only for dry hair?
No. Elixir Ultime can fit damp-hair styling as well as dry-hair finishing. The amount and placement matter more than treating “oil” as a product only for one hair type.
Which shampoo should go with it?
Choose shampoo and conditioner around your wider needs, such as colour care, dryness or damaged lengths. Our Kérastase range guide helps you build the wash-day foundation before choosing an optional finishing step.
Explore Kerastase at Flawless Body and check the current product page for sizes, ingredients and availability.
Product guidance: manufacturer’s information. Follow the directions on your own packaging, which may change with product updates.