A clinically tested leave-in serum and scalp massaging serum applicator that helps thinning hair become thicker, denser and healthier over time. This lightweight, non-greasy leave-in serum contains a clinically-tested blend of nutrients including Caffeine, Kelp, Centella asiatica, and Biotin to help address thinning hair, while the massaging comb helps promote better scalp circulation. Both the Superpower Liquid Comb and Superpower Fortifying Hair & Scalp Serum are designed to work with all hair types and textures. The serum is sulfate-free, paraben-free, cruelty-free and safe for color- or chemically-treated hair.