6 Things Your Skin Is Doing When You're Sleeping

Illustrated by Mary Galloway.
We don't need to tell you that sleep is important — everyone knows that. It's the reason you sometimes have to skip a girls' night or finish a work project in the a.m. instead of staying up late. But, aside from giving you the ability to function properly, sleeping seven to nine hours a night also allows for much-needed repairs to happen on the cellular level.

To understand why hitting that sweet spot is so important, we went to Dr. Jessica Wu, a board-certified dermatologist based in Los Angeles. She confirmed what we always knew: Beauty sleep is an actual thing — if you go through each of the five stages of sleep, that is. "Not hitting all the stages, which last an average of 90 minutes each," she says, "means you're not getting all of the benefits of sleep."

So, what is it exactly that our skin does at night, and how does sleep help? From info on boosting collagen production to tips for hydrating overnight with a sleeping mask, like Olay Regenerist Luminous Overnight Mask, here's what you need to know. Only thing we're not sure about? If sleep is a viable excuse for being late.
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Illustrated by Mary Galloway.
Collagen is responsible for that youthful perkiness in our skin. The protein is naturally found in our skin's connective tissues, but it comes in limited supply — production slows as we age and can decrease at an even faster rate if we're not getting seven to nine hours of shut-eye each night.

During the third and fourth stages of sleep, your body goes into repair mode and produces cells and hormones that help boost collagen production. If you sleep poorly, according to Wu, there are increases in certain immune hormones that prevent collagen production.
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Illustrated by Mary Galloway.
A good night's sleep doesn't just keep you from feeling terrible. It keeps you healthy, and that includes your skin. The areas around your nose, mouth, eyes, and ears are lined with a mucus membrane, which is a layer of tissue that helps keep harmful bacteria from entering the body. However, that barrier can be compromised if you don't get your ZZZs, says Wu. Miss enough sleep, and a compromised immune system can lead to larger issues, like skin-related autoimmune disorders such as psoriasis.
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Illustrated by Mary Galloway.
During the first four stages of non-REM, or NREM, your body temp drops a few degrees from the average of 98.6. And, when your body cools down, you sweat and lose moisture in your skin.

Now, the sweat isn't enough to soak your jammies, but it's enough to dry out your skin if you don't properly prep it before bed. To combat and keep the moisture in, try a sleeping mask like Olay Regenerist Luminous Overnight Mask. It not only hydrates as you sleep, but it can help with your skin's overall hydration level if you continue to use it on a regular basis.
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Illustrated by Mary Galloway.
"Good sleep regulates blood sugar while poor sleep interferes with glucose levels and metabolism rates," says Wu. While that may sound like it has nothing to do with your skin, it actually has everything to do with it.

This interference can make you crave unhealthy, simple carbs like white bread and refined sugar. When your body processes those simple carbs, it results in glycation, a chain reaction that increases inflammation and produces enzymes that break down the collagen in your skin. And, as you've already read, collagen comes in limited supply.

Side note: Why does everything end up breaking down collagen?
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Illustrated by Mary Galloway.
Yes, human growth hormone can come in pill or shot form from a doc, but the type we're talking about is created naturally in your body as you sleep. As we age, production of HGH — just like the production of collagen — slows down.

"In deep sleep, your body secretes human growth hormone during childhood to teenage-hood to adulthood — but in increasingly smaller amounts," says Wu. "This is why it gets harder for us to build muscle and one of the reasons why our skin gets thinner as we age."

The less sleep you get, the less HGH you produce, the thinner your skin can be — all the more reason to get some serious shut-eye.
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Illustrated by Mary Galloway.
Melatonin — just like HGH — is mostly known as a human-made supplement, used as a sleep aid. But, during sleep, your body naturally produces the hormone as a way to repair itself when the lights go out. And, we don't mean that just figuratively — melatonin is literally produced when your body recognizes darkness, hence why you (should) sleep in the dark.

It's actually much more than just another body-repairing hormone, though. According to studies, melatonin has been shown to act as an antioxidant, reducing the amount of internal and external free radicals, like inflammation and cigarette smoke respectively, that react negatively with your cells. It can also help block out harmful ultra-violet rays that can damage cells. Think of it as nature's own sunscreen — but, yes, you still need to wear the real thing.