That's why dermatologists keep coming back to one piece of advice: don't go to bed without washing your face. Cleansing removes the layer of oil, sunscreen and impurities so that products applied afterwards can work more effectively. Acne-prone skin may flare upIf your skin already tends to break out, sleeping without washing your face can make things worse. Dermatologists generally recommend washing your face twice a day, including before bed, to help reduce the build-up that contributes to acne. If you accidentally fall asleep without washing your face after a long wedding, a late-night flight or an exhausting workday, it’s alright.