No one likes having a greasy face, but oftentimes, what we do to combat the oil leads to the production of even more oil. “Oily skin happens when the sebaceous glands in the skin make too much sebum,” explains Dr. Gretchen Frieling, a board-certified dermatopathologist in Boston. “Sebum is the waxy, oily substance that protects and hydrates the skin, and it’s essential for keeping the skin healthy. However, too much sebum can lead to oily skin, clogged pores, and acne.” According to Dr. Joshua Zeichner, director of cosmetic and clinical research in dermatology at Mount Sinai Hospital, how much oil your skin produces is determined by your genes. “While you can’t change your genetics, you can minimize the appearance of oily skin by using specific skin-care products,” he explains.