A leave-in repairing anti-breakage filler hair serum. This anti-frizz serum works to seal and fill hair strands, and protect them from the heat of styling tools, leaving hair shiny and strong.


Kérastase Première Sérum Filler Fondamental is a lightweight leave-in treatment for the inner repair of all types of damaged hair, leaving it glossy and supple.


Because of its increased porousness, processed hair absorbs 3 times more calcium from water than untreated hair, leading to a damaging calcium overdose which is visible inside and outside the hair fiber. Kérastase Sérum Filler Fondamental has a dual action: its light, balmy texture seals the cuticles to shield hair’s surface, while filling the fiber and reinforcing hair strength. Your hair is protected from the calcium damage of hard water, as well as from humidity, and heat up to 450 °F. Frizz is eliminated, and hair is left smooth and supple, easy to style.


For even more care for your bleached or damaged hair, combine with the rest of the Première range. Try the maximum power of the layering technique: Start with the pre-shampoo treatment, Kérastase Concentré Décalcifiant Ultra-Réparateur, then without rinsing off the Concentré, use the shampoo, Kérastase Bain Décalcifiant Réparateur on top. Follow with the conditioner or mask before applying Kérastase Sérum Filler Fondamental as a final repair step.


Benefits: 
Repels humidity
Deeply nourishes
Locks out frizz
Recreates softer and smoother hair
3x smoother hair*
2x softer hair*
99% stronger hair*
72H anti-frizz*
Hair protected from heat, up to 450 °F*