Oily hair is heavy. The scalp and roots shine. Oily hair and scalp are characterized by oily roots and an overall unkempt appearance. The hair is weighed down by the dust retained by the sebum, present in too large quantities on its surface.

This excess is due to the hyperactivity of the numerous sebaceous glands of the scalp which secrete sebum (which surrounds the hair shaft), which gives the hair this oily appearance