Oily skin can be caused by genetics, hormonal fluctuations, and stress.1 All of these factors can stimulate the oil glands, prompting them to produce excess sebum. Products for oily skin can help remove or absorb excess oil. Properly formulated skincare products for oily skin (including cleansers, toners, serums, and moisturizers) can also help minimize the appearance of pores and prevent them from becoming clogged.
1https://www.aad.org/public/everyday-care/skin-care-basics/dry/oily-skin