How important is good sleep for good skin? Plenty, say RealSelf dermatologists. While a solid eight hours of shut-eye may not be as important as wearing sunscreen regularly, getting enough sleep means more to your skin than exfoliating regulating or drinking eight cups of water a day.

But it’s not just how long you spend shut-eyed that matters. Turns out your body is hard at work even as you snooze so you need to prep it for success.

Cleansing every night is so important because as we sleep, our skin takes advantage of this time to naturally rejuvenate and heal itself,” says board-certified dermatologic surgeon Dr. Joel Schlessinger. “Cell turnover is also more active while we sleep and this process isn’t as effective if skin isn’t clean.”

That means removing makeup is non-negotiable. Doing so can cause clogged pores, breakouts, and premature signs of aging, among other not-so-nice skin situations.

“The makeup, oil, and environmental pollutants that gather on skin all day seep into pores, causing breakouts and speeding up the aging process,” explains Dr. Schlessinger. “Plus, makeup attracts harmful free radicals throughout the day and these free radicals lead to collagen breakdown, aging skin faster.”

“As we sleep, our skin takes advantage of this time to naturally rejuvenate and heal itself.”

Even just leaving eye makeup on can cause dryness, redness, and infection, he adds. A quick tip for the more forgetful: stash makeup remover wipes on the nightstand. “These won’t remove impurities entirely, but at least you won’t be sleeping in your makeup,” says Dr. Schlessinger.

If wrinkles are a top concern, consider a new sleeping position. So-called “sleep wrinkles” are the natural result of pressing the face against a pillow every night.

The best way to avoid sleep wrinkles is to sleep on your back, which prevents your skin from coming in contact with your pillow,” says Dr. Schlessinger. “This sleep position also has other health benefits, including less neck pain and better back alignment.”

Related: Wrinkle Treatment Overview

Finally, check the thermostat before bed. Cooler temperatures often mean less moisture in the air, which may mean drier, tighter, more uncomfortable skin. To avoid irritation, use a humidifier. “Always set the unit below 60% humidity,” suggest Dr. Schlessinger. Otherwise, you’ll wake up to dewdrops, not dewy skin.

For more tips to sleeping your way to better skin and to speak with Dr. Schlessinger, contact media@realself.com. Learn more about skin care options at RealSelf.