Kérastase Première Sérum Filler Fondamental for Damaged Hair 90mlThe Krastase Premire Srum Filler Fondamental is a lightweight, leave in hair serum engineered for the deep inner repair of all damaged and chemically processed hair types, delivering a visibly glossy, supple, and resilient finish with every use. Processed hair is significantly more porous than untreated hair, causing it to absorb up to three times more calcium from water, which leads to a damaging calcium overdose that weakens the hair fiber from the