Nioxin Anit-hair Loss Serum. Leave-on hair treatment that thickens the hair from the 1st use and reduces hair loss in 8 weeks thanks to improved hair anchorage and therefore thickening your hair. The formula, clinically proven to thicken the hair, increase hair anchorage and reduce hair loss, combines Caffeine, Lauric Acid, Niacinamide and Sandalore™. Sandalore is a trademark of Givaudan.