Nioxin Pro Clinical Hair Fall Defense Serum is a leave-on scalp treatment for thinning hair. Designed for daily use, it is clinically proven to increase hair anchorage with visible results in only 8 weeks* while thickening hair from the very first use. It is 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. *Via improved hair anchorage. average results in 8 weeks, in a double-blind clinical study with 120 panelists.