Beauty Sleep might sound like a myth that’s being peddled on a late-night infomercial, but eight hours of sleep really can help you look and feel your best. Why? It comes down to what happens in your body when you drift off.

• Your Body Pumps Out Healing Hormones.

While you’re sleeping, your body—and your skin—are hard at work healing themselves. During the deeper phases of sleep, your body produces growth hormone, which repairs daily damage from things like sun exposure and pollution and creates new cells so you wake up looking brighter, fresher, and more vibrant. That’s why bedtime can be a great time to apply a hardworking night cream to accelerate the restorative process.

• You Wake Up Less Puffy.

Your body also dispatches its water deliverymen as you snooze, sending moisture where it’s needed and getting rid of the excess. Cut this process short, and you’re more likely to end up with bags and obvious wrinkles. Skimping on rest also increases your levels of inflammation and stress hormones, which can throw your immune system out of whack, aggravating skin problems like acne, psoriasis, and eczema.

• You’ll Be More Likely to Hit Your Goal Weight

It’s easier to resist tempting treats when you’ve gotten a good night’s sleep, in part because being short on sleep can boost hormones in your blood that make you feel extra hungry. In fact, according to researchers at the University of Chicago, well-rested dieters lose as much as 55 percent more fat than sleep-deprived ones.

• You’ll Smile More.

It may seem obvious, but not getting enough sleep increases your chances of feeling down—and that can lead to depression. People with insomnia are ten times as likely to be depressed as those who sleep soundly. And even if you’re not prone to a medical condition like depression, just one week of not getting enough sleep could leave you feeling sad, angry, stressed out, and just generally not on your A-game. The cure: getting back on top of your sleep routine.