“Brushes caked with dirt, oils, and makeup can clog pores with bacteria, leading to breakouts or skin irritations,” says Hadley King, MD, a board-certified dermatologist. Synthetic concealer and foundation brushes should be cleaned at least once a week; that’s because they have pores, which absorb more makeupthan natural brushes, which only need to be cleaned twice per month.
The best way to clean natural brushes is with water and brush cleanser or baby shampoo,” says King. Mix 1 part baby shampoo with 4 parts lukewarm water, dip bristles in, and then massage. Or if you’re using brush cleanser, wet bristles, place a drop of cleanser in the palm of your hand, gently dip the bristles in, and then massage. Then rinse, squeeze out the excess moisture, and reshape the brush head, letting it dry with the bristles hanging off the edge of a counter, says King. (Here are the makeup brushes every woman needs.)
Use dishwashing liquid, like Dawn, to clean synthetic brushes, since they need to be stripped of oil and buildup. Apply a bit of Dawn to the brush, then massage the bristles or clean them on a brush mat like the Sigma Spa Express Brush Cleaning Mat, rinsing and reshaping the head to let dry.

“It’s just as important to clean your makeup sponges as it is your makeupbrushes,” says Lori Taylor Davis, Smashbox Global Pro Lead Makeup Artist. That’s because dirty ones can “cause a cream or liquid foundation to go on splotchy or uneven.” According to Davis, the best way to clean a makeup sponge is with a dishwashing liquid like Dawn; the petroleum will cut through the cosmetic oils and silicones coating the material.” (These 7 foundation mistakes are making you look older.)

Breakouts aren’t fun, but an even more extreme risk of not cleaning your brushes regularly is spreading viral infections—either ones you had before, or ones from someone else if you’re sharing tools, says Davis. So clean those brushes regularly, especially if you’ve just been sick.

“Using brushes that have significant buildup on them can clog up pores, leading to milia,” says Shawn Fisher, national makeup artist for Japonesque. Milia, a grouping of cysts which look like small white bumps, typically appear on the nose and cheeks. And unlike zits, you can’t pop ’em—you’ll have to see your derm to get rid of them.

Never clean that facial cleansing brush? You should start. These tools are usually stored in damp places like the shower, where bacteria and yeast love to hang out and multiply. Yeast is naturally found in our environment and on our skin, but an overgrowth can cause skin irritations and red scaly or raw patches. “If you clean it weekly, a brush head should last 3 months,” says King. “Place a few drops of antibacterial dish soap on your fingers or on a toothbrush, and scrub the bristles and crevices. Rinse with warm water, then allow the brush head to air-dry overnight.”
Prevention