Nanogen hair thickening fibres dark brown helps give you an instant look of fuller hair its ultra fine hair fibres bind to your hair for instant hair thickening and hair volumising developed with pure keratin just like your hair it is safe to use on your scalp stays all day long developed with patented kinetic technology it helps hair fibres stick to your hair using static electricity meaning that the fibres stay in place all day long through rain perspiration or wind unique features