We’ve all heard the phrase “beauty sleep,” right? It’s been floating around since the 1800s, and I’m willing to bet most of us have experienced its truth firsthand. I know I’ve had nights where I couldn’t sleep, or stayed out late and you can see it the next day in my skin. But have you ever wondered if this whole “beauty sleep” thing is just an old wives’ tale, or if there’s some science to back it up? Can sleeping really help skin conditions?

Spoiler alert: there is science behind it—and quite a bit, actually! Our sleep quantity and quality impact our whole body, which can then have a knock-on effect on our skin. It’s one of the most important foundations to get right for your skin and overall well-being.

What Happens When We Sleep?

Sleep isn’t just about giving your brain a break and helping you have energy for the next day. When we drift off, our body kicks into repair mode.

NON-REM VS REM Sleep

Sleep runs in cycles, and each cycle includes REM (rapid eye movement) and Non–REM sleep. On average, one complete sleep cycle lasts about 90 minutes, and you typically go through 4 to 6 cycles per night, depending on how long you sleep (and this is why it’s important to get those 7-8 hours per night).

When you first drift off to sleep, you’ll enter non-REM sleep. There are different stages to non-REM sleep but essentially this is the part of sleep where your body is going into a bit of a deep clean and repair stage.

After the stages of non-Rem sleep are complete, you’ll move into REM sleep. This is like the brain’s creative party. Your eyes move around rapidly under your eyelids (that’s what REM stands for – Rapid Eye Movement), and your brain is super active—almost like you’re awake, but your body is in “do not disturb” mode.

This is when you dream the most. Your brain is busy organising memories, solving problems, and even sparking creativity. Have you ever woken up with a solution to a problem, or noticed the thing you were stressing about the night before isn’t that big of a deal? That’s REM doing its magic. It’s also crucial for emotional health – and has been called ‘overnight therapy’. REM helps you process feelings, which benefits your mental health. Reduced REM sleep has been linked to a higher risk of anxiety and depression.

How Lack of Sleep Affects the Skin

Ok, now you know the basics of sleep. Let’s get into how lack of it could be affecting your skin. Poor-quality sleep affects every system in your body—and your skin isn’t exempt. Here’s how lack of sleep affects your skin:

Increased Cortisol Levels

When you don’t get enough sleep, your body perceives it as a form of stress. This triggers the release of cortisol (our body’s stress hormone), keeping your body in a heightened state of alertness. Higher levels of cortisol from sleep deprivation also make you more emotionally reactive. It causes the emotional center of the brain (known as the amygdala) to become overactive, and the rational thinking part of the brain (the prefrontal cortex) to be reduced.

While short-term stress won’t cause huge issues with your skin. I’m sure we’ve all experienced a flare-up in our skin condition during long-term periods of stress. This can be a tricky one though as being stressed can massively impact sleep, and then the lack of sleep is making you feel more stressed.

Weakened Immune System

Your immune system takes a hit when you’re sleep-deprived. You know when you’ve got a cold and all your body wants to do is sleep? Well clearly, your body knows what it needs. Because sleep helps your immune system function at its best. If you’re sleeping less than 6 hours a night, your skin might struggle to repair itself, and those breakouts might seem like they’re taking forever to clear.

Food Cravings

Ever noticed how a bad night’s sleep leaves you craving all the food the next day? You might notice that you also can’t satisfy those cravings. No matter what you’re eating, you just keep wanting more. That’s because sleep deprivation messes with the hormones that regulate hunger and satiety. Unfortunately, those high-sugar, processed foods do zero favours for your skin.

Affects gut health

So you probably know by now that sleep is when the whole body rests and repairs. But you might not have realised how much sleep helps your gut repair. And the gut-skin connection is real. Sleep is essential for normal digestive processes and a healthy gut microbiome. Low-quality sleep has been linked to increased symptoms of indigestion, bloating, and discomfort.

As well, if you eat too close to bedtime, your body is still busy digesting food while you’re trying to sleep. This can prevent you from reaching the deeper stages of sleep. As a result, your sleep may be more restless or lighter. Your gut might be off balance, and your skin might be struggling to stay balanced and healthy.

How to support sleep for healthy skin

Tips for Better, Restorative Sleep

When I first got into nutrition and learnt how important sleep was, I became completely obsessed with it. In fact, it triggered insomnia. I was so obsessed with making sure that I got deep, restorative sleep that it stressed me out and pushed me further away from it. So, while I am explaining that sleep is important, I don’t want you to stress yourself out like I did. However, if you are struggling with insomnia I’d highly recommend How To Sleep Well Every Night by Guy Meadows.

But if you do want to try some things to help sleep, I find these useful:

1. Reduce Caffeine After 2 PM: Even if you think caffeine doesn’t affect you, it probably does. While this does depend on your genetics and how quickly your body can clear out caffeine, on average it takes around 7 hours to leave your system. So if you want to be asleep by 10 pm, stop drinking caffeine 7 hours before. It might not stop you from falling asleep, but it can prevent you from reaching deep, restorative sleep. And yes, even decaf has a little caffeine in it!
2. Swap your evening drinks: Alcohol might help you fall asleep faster because it helps you feel calm and relaxed, but it disrupts deep sleep stages. What you might notice when you drink alcohol is that you keep waking up in the night. It can cause you to have little ‘micro-sleeps’. Alcohol also causes dehydration. So, you’ll wake up feeling groggy—and your skin will look a bit dull.
3. Stick to a Routine: Going to bed and waking up at the same time every day—yes, even on weekends—helps regulate your sleep-wake cycle. Try to get outside in the morning; sunlight hitting your eyes helps suppress melatonin and tells your body it’s time to wake up.
4. Try Calming Herbs: Herbs like lavender, chamomile, passionflower, lemon balm, and valerian can help relax your body before bed. If you’re prone to waking up at night, have these as tea earlier in the evening, around 6-7 PM.
5. Magnesium Salt Baths: Magnesium helps calm your nervous system, and a warm bath with Epsom salts or magnesium flakes can help your body absorb it. For extra relaxation, try bath milks or oils that contain lavender and other calming scents.

When Sleep Issues Go Beyond the Basics

There are a lot of things that can hold us back from sleep. You might have young babies or children, and if this is the case I would recommend trying to get some naps in somewhere in the day (if you can, I know it’s difficult to catch a break!). Or you might be dealing with hormonal changes—like during menopause—or you might find that your eczema is itching in the night and keeping you up. Nutritional therapy can offer some support to help correct any underlying imbalances which could help you get a better, more restorative sleep.