The answer I’m supposed to give is: after every use. But to quote a wise woman from one of the greatest viral videos of all time: “Ain’t nobody got time for that!” This is one of the beauty admin things I’m terrible at; I often leave them until a makeup artist friend intervenes in disgust, or after trying to apply a brown eyeshadow and it comes out blue because that’s what I used the brush for previously.
Dirty brushes collect sebum and dead skin, and thus become a breeding ground for bacteria that could cause rashes and acne. The American Academy of Dermatology also says that “Dirty makeup brushes can cause an infection, E coli or a staph infection, which can be very serious.”
