this thickening serum hydrates and strengthens fragile hair. formulated with rice water to strengthen and repair, izumi tonic serum leaves hair 30x stronger* and reduces split ends by up to 91%*. this leave in treatment serum is powered by ceramides, perfect to thicken and increase hair diameter for hair lacking volume. apply after styling to add texture, thickness, shine and hold. inspired by a japanese haircare tradition, the izumi tonic range is formulated with rice water, known to restore damage, prevent future breakage, and reveal healthier & smoother hair. we source our rice water from hyogo, japan in an eco-friendly manner.