What are the three main functions of the sebum secreted by the scalp?

Sebum secreted by the scalp serves three main functions: it moisturizes and protects the hair and scalp, preventing dryness and brittleness; it provides a natural barrier against environmental factors, helping to shield the skin from pathogens and irritants; and it contributes to the maintenance of the scalp’s pH balance, which supports a healthy microbial environment. This oily substance also enhances hair shine and manageability.