Do beards grow faster when you sleep? [The science]

Some people find that their beard seems to grow faster at night time. Perhaps you shave in the morning and don’t notice much grow throughout the day but then it the next morning it is bigger and thicker than you thought it could get. It may be that your beard looks bushy in the morning and so you equate that with your beard faster while you are sleeping. But is this the case? Do beard really grow faster when you sleep? In this article we are going to go over everything you need to know about growing a beard and what you can do to make your beard grow faster – sleep or otherwise.

Studies have shown that sleep deprivation decreases beard hair growth. 19% decrease in beard growth was seen after 48 hours of sleep deprivation. Therefore getting a good amount of sleep means that your hormonal regulation will be better and your beard will grow faster.

However, beards do not grow faster when you sleep it is more about perception than a real increase in growth rate.

Even though beard hair does not grow faster while you are sleeping getting a good night sleep is a very important part of growing a strong and thick beard. In this article we are going to cover everything you need to know about sleep and the growth rate of your beard.

What the science says

A study in 2004 looked at the relationship between sleep disorders and the amount of testosterone in men. If we are going to have a look at the growth rate of hair we should understand the importance of sleep on the levels of testosterone so that we can be sure that the growth of the hair is not inhibited by the amount of testosterone present.

Testosterone is produced throughout the day. They are higher upon waking and D creased to a low point at the end of the day. So, from this we know that you need to get a good nights sleep to have a good amount of testosterone at the beginning of the day. There are bursts of testosterone production that occur about every 90 minutes or so throughout the day, as well.

As you are sleeping testosterone levels begin to increase with the onset of sleep. And, particularly in young men, they reach a peak of testosterone in the first rapid eye movement sleep episode and remain at that level or until they wake up.

You need to be asleep for at least three hours (with a normal sleep pattern) to see the increase of testosterone associated with sleeping.

So, even though we know that getting a good night sleep is instrumental in determining the amount of testosterone that is in the body – does this impact of sleep on testosterone have any impact on the amount that grows overnight.

I can’t find any specific science that says that beard hair grows faster at night. However, I did find an article from 1987 which looked at the effect of sleep deprivation on beard hair growth in men. As part of the study, 10 young men underwent sleep deprivation for 48 hours which resulted in a 19% decrease in their beard hair growth. This effect was related to the hormonal disturbance (which is really the decrease of growth hormone release) and the decrease of dihydroxy testosterone or DHT.

In this study, 10 adult men were deprived of sleep during 48 hours stop they are asked to spend the nights of the control. At home and to avoid large variations in ambient temperature and they had to go to bed between 10 and 12 PM and refrain from any sexual intercourse – which would affect the testosterone levels in the body. During the deprivation. The subjects remained in the lab listening to music and were kept awake for 48 hours. So, this tells us that if you do not sleep your beard hair doesn’t grow. We have to really be careful that we don’t equate back to most of the hair growing at night. This study highlights the importance of sleep on the regulation and production of growth hormones and DHT.

So, the science is a little bit indifferent to this question. No one, as far as I can tell, has actively investigated this subject. We know that hair grows at a relatively continuous rate and that rate is dependent on your body being as healthy and well nourished as possible. However, your hair growth is directly related to your metabolism and sleep and a natural circadian rhythm also has implications for your metabolism.

Hair growth and relationship to metabolism

Human hair growth is connected to your over or metabolism rather than directly linked to your sleep cycles.

A study that was published in 2018 looked at the effects of light at night on metabolism. Because life on earth has evolved during the past several billion years under relatively bright days and dark night conditions the widespread adoption of electric lights could be affecting your metabolism. In this article they looked at night shift workers and their elevated risk for metabolic disorders and also looked at evidence from animal studies. Night shift workers have a higher chance of being obese and having a dis-regulated metabolism that they presume is a direct result from having a disrupted circadian rhythm.

This study found that any interruption to your sleeping with light can quickly affect your metabolism and cause you to put on weight (this means your metabolism is lowered) however, you can increase your metabolism again by exercising and so any issues that you have with sleep patterns can easily be undone with exercise.

That is a pretty cool thing to realise and something that can definitely help your beard growth.

Once again, this is not direct evidence that your beard grows faster at night but much rather that sleep is very important to maintain a healthy metabolism for your beard growth.

Another study published in 2009 looked at the metabolic rate and fuel utilisation during sleep which was assessed by a whole-body indirect calorimetry method – this just means they had a massive air tight room and measured how the carbon dioxide and other gases changed throughout the course of the night. By looking at the carbon dioxide concentration they were able to infer the metabolism of the person in the room. It was found that energy expenditure was greatest during the rapid eye movement portion of the sleep than in the later stages. So the only time in which you may have a greater metabolic rate is during the short rapid eye movement part of sleep and whether or not that has a significant effect on the rate of your beard hair growth has yet to be determined.

Even though this science doesn’t support, nor deny, that beards grow faster at night there are some reasons why your beard may look longer in the morning.

Reasons that your beard may look longer in the morning

Sometimes, because we are so intertwined with our beards and so aware of the minute changes in our beard growth we can convince ourselves that there is something fishy going on when we notice a difference in our beards. In this case, it could be that you think your beard grows faster while you sleep because in the morning you notice a significant difference in your beard length or texture.

There could be some reasons why your beard looks longer in the morning and we should take a look at those right now.

Your beard is fluffy

Bed beard is something that every man with a beard becomes intimately aware of. If you are a particularly restless sleeper your beard can go through a fair amount of trauma and rubbing throughout the night.

It could be that your beard is becoming fluffed up overnight and all of the extra movement against the pillow is causing your beard to not lay flat. This could give you the impression that your beard is growing longer overnight and that there is an extra boost of growth while you were sleeping.

Of course the other option is that your beard is flat and that is what makes it look like it has gained extra length overnight.

Your beard is flat on one side

If you sleep on your sides or front you can flatten one side of your beard. This flattening on one side of your face can make it look like your beard is longer than the other side. Beards are typically very curly and wiry. And, as beard owners, we spend a lot of time trying to make the beard lay as flat as possible and grow down. If you want to read more about why your beard is so wiry and what you can do about it I’ve got another science-based article – click here to read why your beard is so wiry

If you want to know more about training your beard to grow down and lay as flat as possible check out my YouTube video below:

Your pillow is causing static

Your pillow is probably the only bits of material that your beard rubs up against for many hours each day. If you have a synthetic pillowcase you can easily cause static to build up within the hair which will make it look cushier and longer in the mornings.

There are a couple of things you can do about this including buying a beard wrap for sleeping. For my full comparison guide for the best beard wrap for sleeping check out this article – click here.

Your stubble seems longer in the morning

It could be that your stubble seems particularly long in the morning. If you have a busy morning and you shave at night you may have noticed that when you wake up in the morning the stubble is longer than you would expect it to be based on the growth throughout the day.

The thing is – your hair grows at the same rate at all times it’s just that in the morning you are noticing its growth more.

Imagine this, throughout the day you’re distracted by all sorts of different things and so you don’t pay much attention to your beard. It’s kind of like how “a watched pot never boils”. It grows but you don’t notice it. However, if you shave at night and go to sleep the next point of reference is the morning where you’ve had a whole night’s growth and you notice it immediately.

This could give the illusion that your beard grows more at night than it does during the day.

How fast does facial hair grow per day?

On average, the growth rate for human hair is about 1.25 centimeters or 0.5 inches per month, or about 15 centimeters or 6 inches per year. The rate is about 0.35 millimeters daily – think of it like this and you probably won’t get annoyed!

The actual “length” of your beard will also depend on if your hair is straight, wavy or really curly as the length will be as long as your beard falls from your face.

The average person can expect to grow anywhere between 12 and 36 inches before their hair stops growing and falls out.

On average here’s the amount of time it takes to get to each length:

000Clean-shaven. to fuzzy stage.
212.5You need to have a good shape up here.
637.5Your chin is full and impressive front on.
8410Looking like a long beard.
10512.5Substantial beardage.

For more information check out my other blog – Will your beard stop growing? Busting the myths!


So, beards have not been proven to grow faster at night or while you are sleeping. The rate of your beard growth is directly correlated with your metabolism. There are a few metabolic studies which have looked at the rate of peoples metabolism while they are sleeping and they find that it is highest when there is rapid eye movement sleep.

If you want to make your beard grow faster you do have to make sure that you do have a good night’s sleep. As any sleep deprivation can result in a disruption in your hormonal system which can impact your testosterone and therefore the amount of hair that you grow on your face.

The Author

Andy Stapleton

Andy is a writer and YouTuber with a PhD in science. He has written and/or produced videos for Science Alert, COSMOS magazine, and Australia's Science Channel among others. He is an avid beard grower and after many years of growing and trialling different beard styles, he started this blog to share the tips, tricks, and science that he has learned along the way!