Eyelash serum is a cosmetic product designed to enhance the appearance of eyelashes. It typically contains ingredients that promote growth, strength, and thickness, helping to achieve longer and fuller lashes. Many serums are formulated with peptides, vitamins, and botanical extracts that nourish the hair follicles. Users apply eyelash serum daily, usually at the base of the lashes, similar to applying eyeliner. Results can vary, but many people notice improvements in lash length and density after several weeks of consistent use. Popular brands include Latisse, Revitalash, and GrandeLASH.