What is the function of sebum on the scalp?

The function of sebum on the scalp is primarily to lubricate and protect both the hair and the skin. Sebum is an oily substance produced by sebaceous glands that helps to coat the hair shafts, providing moisture and preventing dryness. This natural oil also creates a barrier that protects the scalp from environmental factors, such as bacteria and fungi, which can lead to irritation or infection. By keeping the hair and scalp moisturized, sebum plays a crucial role in maintaining overall hair health, preventing brittleness, and ensuring that the hair remains shiny and manageable.

Other options, while related to hair care, do not accurately describe the primary function of sebum. For instance, while some factors can influence hair growth, sebum does not directly enhance it. Likewise, sebum does not provide color to hair, as hair color is determined by melanin located in the hair follicles, and sebum does not contribute to hair volume.