Beauty sleep: what sleep does for skin and hair

What beauty sleep means

The English expression has been around for more than a century and referred to sleep in the first hours of the night, which was said to be good for appearance. Today it is used in two senses. The first concerns sleep itself: sleeping enough and regularly shows on the face. The second concerns the bed, that is pillow, pillowcase and temperature, which stay in contact with skin and hair for seven or eight hours.

The first sense has controlled studies behind it, with photographs and observers. The second has more modest foundations, made of mechanics and common sense: the pressure of the face on the pillow, the rubbing of hair on the fabric, the moisture that stays on the pillowcase. Here they are kept separate, because confusing them leads to promising from the fabric what only sleep can give.

The focus of this guide stays on appearance. The climate of the bedroom for sleeping better has its own guide on theideal environment for sleeping, with temperature, humidity and darkness.

The face after a short night: what the studies measure

The work that gave the expression a foundation is titled, precisely, Beauty sleep and appeared in the BMJ in 2010. A group at the Karolinska Institute in Stockholm photographed 23 adults aged 18 to 31 twice: after a normal night of 8 hours and after 31 hours of wakefulness. It then asked 65 people, who did not know which photo was which, to rate each face on scales from 0 to 100.

The faces after wakefulness were judged less healthy (63 versus 68), more tired (53 versus 44) and slightly less attractive (38 versus 40), with statistically robust differences (source: Axelsson et al., BMJ 2010). The authors note that a good part of the effect comes from the tired look: the viewer reads fatigue and translates it into a judgement about health.

In 2013 the same group looked for the details that make that difference. Ten people photographed before and after wakefulness, 40 observers, ten facial signs rated one by one. Drooping eyelids, red and swollen eyes, dark circles, pallor, wrinkles and fine lines, and the corners of the mouth got worse. Glazed eyes, skin redness and tension of the lips did not change (source: Sundelin et al., Sleep 2013).

The third study is the closest to real life, because it does not use a sleepless night. Twenty-five people slept 4 hours for two nights in a row and, in another period, 8 hours for two nights. The photos after the short nights were judged by 122 observers as less attractive and less healthy, and the viewers said they were less inclined to spend time with those people (source: Sundelin et al., Royal Society Open Science 2017).

Two cautions. The numbers are small, dozens of people, and the differences are a few points on a scale of 100: they show up on average and may escape notice on a single face. And the studies measure how a face looks to others: the health of the skin falls outside their measures. They remain, all the same, the most solid basis that exists on the subject.

What the skin does while you sleep

The skin follows a 24-hour rhythm like the rest of the body. A 2019 review summarises the main data: the multiplication of cells in the surface layer peaks around midnight, the repair of DNA damaged by ultraviolet is more efficient at night, and the permeability of the skin is higher in the evening than in the morning (source: Lyons et al., Journal of Clinical and Aesthetic Dermatology 2019).

Skin that is more permeable in the evening also loses more water. That is why many moisturisers are recommended for the evening: night is the moment when the barrier works and rebuilds itself.

What happens when sleep is poor was looked at by a study of 60 women aged 30 to 49, divided into good and poor sleepers with a standard questionnaire. After stressing the barrier with adhesive tape, at 72 hours the good sleepers had recovered 30 per cent more, and rated their own appearance better (source: Oyetakin-White et al., Clinical and Experimental Dermatology 2015). The study observes an association, and people who sleep badly often also have other habits that weigh on the skin.

How many hours you need and how much regularity matters

The reference figure for an adult is 7-9 hours a night (source: NHS, insomnia). The need varies from person to person, and the most reliable signal remains the day: anyone who is tired every afternoon probably sleeps less than they need.

The studies seen above suggest that the face registers even short deficits: two nights of 4 hours are enough to change the viewer's judgement. The opposite also holds, in the practical sense that matters: catching up on sleep in the following days brings the most visible signs, such as dark circles and puffiness, back to their usual level.

Regularity matters as much as duration. Going to bed and getting up at the same time, even at weekends, supports the 24-hour rhythm on which the skin works. The same NHS source recommends a dark and quiet room, with curtains, blackouts or an eye mask if needed, and flags a room that is too hot or too cold among the causes of disturbed sleep.

Position and pressure on the face

People who sleep on their side or on their front rest a cheek on the pillow for hours. The skin is compressed and dragged, and in the morning the marks of the pillowcase remain, which usually disappear within a short time. A paper published in Aesthetic Surgery Journal in 2016 distinguishes these compression lines from expression lines, which come from the muscles of the face: the former follow the sleeping position and appear on the side you sleep on (source: Anson, Kane and Lambros, Aesthetic Surgery Journal 2016).

There are two levers. The first is position: sleeping on your back removes the pressure, but few can change a habit of years, and the important thing remains sleeping well. The second is the pillow: a height suited to the shoulder prevents the face from sinking in and folding. How to choose shape and height is explained in the guide to bed pillow sizes.

The subject of pillow marks on the face over the years has a dedicated guide, the one on pillowcases and sleep marks on the face. Here the practical point is enough: pressure depends on position, friction on the surface over which the face slides.

What to ask of a pillowcase

During the night the head moves dozens of times, and with each movement skin and hair slide over the fabric. A smooth surface offers less resistance than a rough weave or terry: it is elementary mechanics, and applies to silk, satin and viscose. The comparison between the two smoothest fibres is in the guide to silk or bamboo sheets.

On hair, friction is noticed above all when it is curly, long or treated: on waking it is more tousled on the side that rested on the pillow. The choices for those with this problem are in the guide to pillowcases for curly hair.

Beyond the surface, three details matter. The closure: an envelope closure, with no zip or buttons, leaves no hard points under the cheek. The size: a pillowcase that is too wide wrinkles, one that is too tight pulls and compresses the filling, and how to measure is in the guide to pillowcase sizes. The certification: OEKO-TEX Standard 100 attests that the finished fabric has been analysed for harmful substances (source: OEKO-TEX, Standard 100), and it is the data point to look for in an item that is on the face every night.

An example with verifiable data: the white bamboo pillowcases from Looniva are in 300TC bamboo viscose, certified OEKO-TEX Standard 100 class I, the class designed for children's articles up to 3 years.

Factor	What happens at night	What you can do
Hours of sleep	below the need, dark circles, puffiness and pallor appear	aim for 7-9 hours, with regular times
Position	on your side the cheek stays compressed for hours	pillow at shoulder height
Pillowcase surface	skin and hair slide with every movement	smooth fabric, closure without zip
Pillowcase cleanliness	sebum, sweat and residue build up	frequent changing, gentle washing
Heat and humidity	sweat stays between face and fabric	fibre that absorbs vapour, cool room

A clean pillowcase: what builds up and when to change it

The pillowcase collects what the face and hair release at night: sebum, sweat, dead cells, cream residue, make-up, conditioner and styling products. There is no official frequency, and the numbers circulating online are advice with no measurements behind them. The practical criterion is simple: change the pillowcase at least when you change the sheets, and more often if your skin is oily, if you use rich creams in the evening or if you sleep with treated hair.

A common trick is to turn the pillowcase over midweek, or to keep a spare pair to alternate. Anyone who suffers from spots or has reactive skin should talk to a dermatologist: the pillowcase is one factor among many, and does not replace treatment.

The wash should be chosen according to the fibre. Bamboo viscose needs 30 degrees, a delicate programme, no bleach and air drying; the complete rules are in the guide to how to wash bamboo sheets. A fragrance-free detergent is a sensible choice for an item that stays all night a few centimetres from the nose.

Heat and humidity on the pillow

The face sweats less than the back, but on the pillow vapour has few ways out: it stays trapped between cheek and fabric, and anyone who wakes up with a damp pillowcase knows the feeling. Here what counts is how much vapour the fibre can take up.

In standard conditions cotton retains about 8.5 per cent of its weight in moisture (source: ASTM D1909), bamboo viscose about 13 per cent and recycled polyester 0.4 per cent (source: Journal of Natural Fibers, 2025). A synthetic pillowcase therefore leaves vapour on the skin; one in cellulosic fibre absorbs more. It remains a comfort factor.

If the problem is sweating over the whole body, the question concerns the entire bed and has its own guide, the one on bedding for night sweats.

An evening routine in six steps

Nothing that follows requires special products. They are habits that bring together what has been said so far.

1. Always remove make-up, even late in the evening: make-up left on the face ends up on the pillowcase and returns to the skin the following night.
2. Apply cream in good time, half an hour before going to bed, so that it is absorbed instead of passing onto the fabric.
3. Gather your hair softly if it is long, without tight hair ties that mark and pull.
4. Check the room: dark, quiet, neither too hot nor too cold, as the NHS recommends.
5. Set the pillow at the right height, so the face does not sink in and the neck stays in line.
6. Keep fixed times for going to bed and getting up, even at weekends.

The step that pays off most remains the sixth. The other five help, but without enough hours of sleep the face shows it in the morning anyway.

The limits: what the bed cannot do

No pillowcase lengthens sleep, erases wrinkles or treats a skin problem. The studies available concern sleep, and none of those cited here measures the effect of a fabric on skin ageing. A fabric can offer a smooth surface, absorb vapour and stay clean easily: these are comfort advantages, and should be presented as such.

The part with solid evidence is sleep: sufficient hours, regular times, a suitable room. The bed plays a supporting role, and its job is not to disturb. Those who want to understand how to read the promises made about fabrics will find the method in the guide to hypoallergenic bedding and the data that support it.

This content is for information only and does not replace the advice of a doctor or dermatologist.

Frequently asked questions

Does beauty sleep really exist?

Yes, in the sense measured by the studies: after a lost night or two nights of 4 hours, observers who knew nothing about the experiment judged the same faces more tired, less healthy and less attractive. The differences are a few points and show up on average. The studies concern the appearance as perceived by the viewer.

How many hours do you need to sleep to see a difference on your face?

The reference for an adult is 7-9 hours a night according to the NHS. In the studies, dropping to 4 hours for two nights was enough for the face to look more tired. The need varies from person to person: if you feel tired every day, you are most likely sleeping less than you need.

Does sleeping on your side cause wrinkles?

On your side the cheek stays compressed and dragged for hours, and in the morning marks can remain that usually disappear in a short time. A 2016 study distinguishes these compression lines from expression lines. Changing position helps, but the priority remains sleeping well, and a pillow at the right height reduces the pressure.

Which pillowcase should I choose for skin and hair?

A pillowcase with a smooth surface, a closure without a zip, the right size for the pillow and certified OEKO-TEX Standard 100. Looniva pillowcases are in 300TC bamboo viscose, measure 50x75 centimetres and cost €39 a pair. Whatever the fibre, what counts is changing it often and washing it according to the label.

How often should you change your pillowcase?

There is no official rule. The practical criterion is to change it at least together with the sheets, and more often with oily skin, rich creams in the evening or treated hair. Keeping a spare pair makes changing easier. Anyone with reactive skin or acne problems should talk to a dermatologist.