Biotin Leave-in Root Stimulator helps rejuvenate and support the hair straight from the root. By encouraging growth, repairing ends and moisturizing the scalp, hair looks and feels denser and more voluminous. Biotin, also known as Vitamin B7, stimulates keratin production in the hair and can help increase the rate of follicle growth. Widely touted as an effective solution to hair shedding and slow growth, Biotin Leave-in Root Stimulator helps stimulate hair at the root for thicker-looking, stronger-feeling hair.