What is Oily skin and who gets it? Oily skin is primarily caused by excessive skin oil (sebum) being produced. During puberty increased male hormones, present in both males and females, Androgen - signals the oil glands of the skin to mature and the body begins producing more skin oil. For some, oil glands can go into overdrive and the skin produces an oily look. This oily appearance normally reduces after puberty, but it can persist into adulthood. It is often seasonally ef