Our skin produces sebum (oil) that’s mostly made up of lipids. This sebum protects us from microbial infections and keeps our skin moist. Along with sebum, our skin produces sweat and sheds dead skin cells.
All these factors combine to form a layer on the skin. People who produce more sebum than others may notice an oilier complexion. Interestingly, hormones and the climate are two main causes of oily complexions.
Hormones
Hormones are the main cause for sebum activation. Some of us are simply genetically prone to produce more oil than others. Overproduction of the hormone dihydrotestosterone (DHT) can trigger an excess of sebum production in the skin, which can then enlarge pores and cause breakouts.
Climate
The climate you’re in can also trigger an oily face. For example, sultry summer months with a lot of heat and humidity may increase oil production.