Smoothing serums are hair care products designed to reduce frizz and enhance shine. They typically contain ingredients like silicones, oils, and proteins that help to coat the hair, making it smoother and more manageable. These serums can be applied to damp or dry hair, providing a sleek finish and protecting against humidity. Many smoothing serums also offer heat protection, making them ideal for use before styling with tools like flat irons or blow dryers. Regular use can lead to healthier-looking hair, as they often help to seal in moisture and prevent damage from environmental factors.