Nioxin 3D Styling Thickening Gel 140ml Looking for definition and hold without stiffness and stickiness? Nioxin thickening gel is the answer – for short to mid-length hair. Just apply. Blow dry. Style. Now’s your time to shine. Try Nioxin 3D Styling Thickening Gel with Nioxin 3D Styling Regular Hold Niospray for a thicker, fuller hairstyle, without weighing down the hair.