Scalp & Hair Treatment The Nioxin System 3 Leave-In Treatment for Coloured Hair with Light Thinning promises visible results within 30 days. This scientifically-formulated treatment is enriched with biotin and niacinamide, providing non-oily moisture to the scalp and strands for fuller and thicker-looking hair with added body and shine. With regular use, it can also help protect against breakage and brittleness, reducing the appearance of split ends and dryness, and leaving hair stronger and more voluminous over time. Ideal for coloured/ dry/ damaged hair