Use it: To spot-treat a blemish fast.
How it works: This top acne treatment is an antibacterial agent, killing the bacteria that cause pimples to form, says Gross. Because benzoyl peroxide is so powerful, it helps blemishes go down quickly; just make sure to use a non-comedogenic moisturizer first to minimize dryness. Try Clearasil Ultra Rapid Action Treatment Cream ($11 at drugstores and drugstore.com).
Good to know: Initially, it can cause dryness and redness. Also, “it bleaches towels and clothes,” says Zoe Draelos, a dermatologist in High Point, North Carolina.