L'Oreal Professionnel Serioxyl Thicker Hair Treatment (90ml)Product Description This serum has an instant thickening effect for thin or fine hair. Enriched with Intra Cylane, a thickening molecule born of ten years research to reveal hair that looks thicker and appears fuller to the touch. To use: Apply a few pumps to wet hair, evenly along the lengths and ends. Leave to dry naturally or blow dry using a hairdryer.