Destined for Density™ MegaStrength+ Caffeine + Biotin Peptide Density Serum is a non-greasy, lightweight formula that absorbs quickly on the scalp. Clinically shown to increase hair density by up to 3X*. It features 5% of our unique follicle support complex including ingredients like copper peptides and zinc that are scientifically proven to help support thicker-looking hair in as few as 16 weeks with daily use.