WHAT IS IT? 8H Magic Night Serum by Kérastase is a beauty sleep high nutrition serum for dry hair. This overnight hair treatment contains anti-dryness polymers for immediate care with a light and non-greasy finish. It also delivers a dose of essential nutrients that boost the formula’s ability to nourish and reinforce the hair. The magical overnight hair serum works for 8 hours to revitalize and regenerate dry hair and protects from pillow friction. Bottle made of 20% recycled glass.