formulated products that are specifically designed to work with our unique hair biology to give you amazing looking thick hair at any age. Hair Biology Hair Thickening Treatment instantly thickens each strand of hair and fights breakage for fuller looking thick hair. Made with biotin and free of parabens, our Full & Vibrant Collection is specially formulated to be safe for thin, flat or thinning hair. Discover the complete line of age-inspiring hair care products from Hair Biology and fall in love with your hair again.