Nioxin Pro Clinical's Anti Hair Loss Serum is a leave-on scalp treatment, clinically proven to reduce hair loss* in only 8 weeks via improved hair anchorage while thickening hair from the 1st use. It's formulated with innovative ingredients including SANDALORE™, caffeine, lauric acid, and niacinamide. Together they work to stimulate and nourish the hair follicles to prolong the growth cycle and improve hair resistance for fuller-looking hair. This effective leave-on scalp treatment is the first time SANDALORE™ has been leveraged to stimulate hair follicles and improve hair anchorage. *By 20% on average