What is the purpose of a hair serum?

The purpose of a hair serum is primarily to provide hydration and reduce frizz. Hair serums typically contain lightweight oils and silicones, which help to smooth the hair cuticle, making it appear shinier and less frizzy. By applying a serum, individuals can achieve a polished look while also sealing in moisture, which is particularly beneficial for hair that is dry or damaged.

While hair serums can sometimes aid in making hair appear thicker temporarily by coating the strands, their most recognized and effective function is not to thicken hair but to enhance its overall manageability and hydration levels. They do not add color to the hair or serve as a drying agent, as those functions are typically attributed to different types of hair products.