On average, humans sleep between seven to eight hours per night (or at least, that’s the recommendation). That translates to approximately one-third of our entire lives. If you’ve ever pulled an all-nighter only to discover dark under-eye circles the next day, you’re probably familiar with just how much sleep deprivation can affect your appearance. Getting enough rest is essential for your physical and mental health—and, as it turns out, it might also be the key to younger-looking skin, too.

Ahead, we’ll break down the basics of beauty sleep and outline the five most dramatic skin benefits of sleep. Plus, we’ll provide recommendations on Kiehl’s products you can use while you’re sleeping for visibly brighter, more hydrated skin come morning. Read on to learn how to sleep your way to healthier-looking skin.

Sleep Basics

You probably know why sleep is good for you health-wise, but you may not be aware of what actually happens when you sleep. Physically, your heartbeat and breathing slow, and your body cools down to conserve energy. Your brain, meanwhile, stays active all night long. While you sleep, your body works to eliminate toxins, buildup, and other waste that accumulates throughout the day. It also releases several hormones, including some necessary to repair muscle, joints, and other tissues.

Experts recommend aiming to get between seven and eight hours of sleep every night, although the exact amount of time depends on factors such as your age and health. Quality of sleep matters, too: Factors such as stress, alcohol consumption, and noise can affect how soundly you sleep. This may lead to cognitive impairment, chronic health concerns, and visible side effects, such as dark under-eye circles.

How Sleep Benefits Your Skin

Sleep and skincare, have a mutually-beneficial relationship. On the one hand, maintaining a relaxing pre-sleep ritual (like a nighttime skincare routine) can help alert your brain that it’s time to prepare for bed. On the other hand, getting enough quality sleep can help improve the appearance and health of your skin.

During the day, skin works to protect itself against the environment. Once night comes and you go to sleep, it switches to stimulating its repair functions to address daily aggressors. This means skin repair and recovery are optimized while you sleep. Skin also becomes more permeable, blood flow increases, and melatonin—which is associated with suppressing UV damage—reaches a high at night.

Sleep can help your skin, and there are also ways you can bolster the relationship. Read on to discover four of the biggest beauty benefits of sleep, plus Kiehl’s overnight skincare products you can use to make the most of your nightly snooze.

1. The Appearance Of Fewer Wrinkles

Collagen and elastin are two proteins responsible for giving your skin elasticity. When these proteins are adequately produced, skin appears firm, plump, and smooth. However, external factors, like stress and fatigue, can inhibit the production of these proteins. Over time, this results in sagging, dullness, and the development of fine lines.

Sleep plays an important role in keeping your skin firm and smooth. Studies show that chronic sleep deprivation can make signs of aging, such as fine lines and wrinkles, appear more prominent. Not getting enough sleep also impacts your skin’s elasticity, which makes you more likely to develop deeper wrinkles.

You can supplement your body’s natural repair processes while you sleep with our best-selling Midnight Recovery Concentrate. This luxurious facial oil contains olive-derived squalane and soothing lavender essential oil. It helps moisturize and smooth the skin. We recommend using this -rich formula every night for a firmer, younger-looking complexion by morning. antioxidant-rich formula every night for a firmer, younger-looking complexion by morning.

For additional anti-aging benefits, incorporate an anti-aging mask into your weekly skincare routine. We recommend Ginger Leaf & Hibiscus Firming Mask, which is formulated with ginger leaf and a blend of hydrating botanical oils. This powerful overnight mask can be used up to five times per week to diminish the appearance of fine lines and wrinkles and help firm the skin. Use it with or instead of your nighttime moisturizer as needed for a visibly smoother complexion.

Kiehl’s Expert Tip: If you frequently have trouble falling asleep, it may be due to your mid-afternoon coffee. Caffeine can remain effective in the body for up to eight hours and make it harder to fall asleep. Keep this in mind when you consider having that third cup of coffee. If you’ll be trying to sleep in less than eight hours, you may want to skip it. Our experts recommend reducing caffeine intake after lunch time.

2. Stronger, More Resilient Skin

Research suggests one of the primary skin-related purposes of sleep is strengthening and repairing the skin moisture barrier. One study found that good sleepers had 30% better barrier repair than poor sleepers did.

In addition to getting at least seven hours of sleep per night, you can help strengthen your skin barrier with a hydrating serum, such as our new Vital Strength Skin-Strengthening Hyaluronic Acid Super Serum. This unique formula boasts an effective blend of adaptogenic herbs and 11kDa hyaluronic acid, a specially-engineered form of hyaluronic acid with a molecule small enough to penetrate the skin’s deeper layers. These ingredients help protect the skin against the damaging effects of environmental stressors, such as pollution and lack of sleep. With regular use, this potent serum is clinically-demonstrated to double skin’s strength.* It also helps visibly reduce fine lines and improve skin texture for a more youthful and radiant appearance.

*Based on Skin Strength Index = Composite average score of skin suppleness, plumpness, and resiliency.

3. Brighter-Looking Eyes

As we mentioned earlier, sleep and appearances are closely intertwined. This is especially true when it comes to the delicate skin around the eyes. You’re probably familiar with how sleep deprivation often results in tired-looking eyes. But, lack of sleep can also lead to more prominent crow’s feet, puffiness, and droopiness around the eyes.

While nothing can make up for a good night’s rest, you can help improve the appearance of sleep-related eye concerns with an effective eye cream. We recommend Midnight Recovery Eye, which is formulated with hydrating evening primrose oil and calming lavender oil. These ingredients help minimize puffiness and diminish the appearance of dark circles for smoother, fresher-looking eyes by morning.

4. Less Frequent Breakouts

While you sleep, your brain works hard to repair your cells. One of its primary nighttime functions is releasing and regulating hormones, such as cortisol (sometimes known as the “stress hormone”). When this process is interrupted by too little sleep (or a lack of quality sleep), you may experience more frequent breakouts. One study found a positive correlation between stress, sleep, and acne. This suggests that sleep deprivation-induced stress can cause and worsen blemishes.

Next: Healthy Skin Habits To Start Now