Does a patchy beard mean low testosterone?

As you start growing a beard, you may be concerned about how patchy the beard looks. Concern about the continuity of a beard is a common issue among men – particularly teenagers in the early stage of growing their beard. The process of growing a beard relies on the production of testosterone to activate beard growth. Once it is activated, it relies on another chemical called DHT to promote the growth of hairs. However, many hairs do not change to thick beard hairs, no matter how much testosterone or DHT is in the body.

A patchy beard does not necessarily mean low testosterone. If there are other symptoms such as low sex drive, erectile dysfunction, issues building muscle, you should see an endocrinologist for diagnosis. It is more likely that your genetics make your beard hairs less sensitive to DHT.

Does a patchy beard mean low testosterone?

The relationship between testosterone and beard growth is one of activation rather than continual growth. When the testes release testosterone in the early stages of puberty, it activates hair follicles to turn from vellus hairs to dark terminal hairs.

Testosterone causes beard hair follicles to grow on the face and doesn’t play much of a role in keeping them active once they have become activated.

Once the hairs have turned from vellus into terminal hairs, the follicles will continue producing dark hair.

You can see this in male to female trans-people. If they have already developed facial hair before transitioning, they will have to remove the hair with laser or electrolysis hair removal. No matter how many hormone-blocking drugs and extra regions they take, it will not change the hair density of the beard.

On the other hand, testosterone given to female to male trans-people causes facial hair to develop. The testosterone catalyses the activation of the hair follicles, and it does not rely on it for continual growth.

The “normal” or healthy testosterone level in the bloodstream varies widely, depending on thyroid function, protein status, and other factors.

According to recent guidelines from the American Urological Association (AUA), a testosterone level of at least 300 nanograms per deciliter (ng/dL) is normal for a man. A man with a testosterone level below 300 ng/dL should be diagnosed with low testosterone.

Having low testosterone can negatively affect beard growth by not activating the hair follicles. For men with clinically low testosterone taking a supplement may help increase beard growth. However, for most people with testosterone within the normal range taking supplements will not help.

Testosterone isn’t the most important aspect

To understand why testosterone isn’t the most important part of the equation, we need to understand how beards develop and grow.

When boys enter puberty, the testicles begin producing the hormone testosterone. It is this hormone that is responsible for growing a beard.

Hair follicles on the face are sensitive to testosterone and what it becomes in the body –dihydrotestosterone (DHT). DHT is made from testosterone by an enzyme called 5-alpha reductase.

Without DHT, there is no beard.

However, there are genetic factors at play that determine the levels of testosterone in the body and how sensitive the hair follicle is to DHT and testosterone.

So, you can see that to grow a beard; you need to have testosterone, the ability to convert it into DHT via an enzyme. Then, the hair follicle needs to be particularly sensitive to this hormone to grow a thick beard.

All of these aspects of beard growth are determined by your genetics.


Take a look at the members of your family who can or cannot grow a good beard. This comparison will be one of the best indicators for you of whether or not you can grow a beard. And also, be a good comparison so you can understand at what age your beard is likely to be filled in.

The genes required to grow a good, thick and lush beard comes from both your maternal and paternal (mum and dad’s) gene pool.

So the most important question to ask yourself is if any of your relatives have a great beard or, at least, the potential to grow a great beard.

The issue is that the inheritance of genes can get pretty complicated. For example, your brother may be able to grow a beard, and you can’t! That’s because your brother, like you, inherits 50% of their genetic makeup from their father and 50% from their mother, BUT they could be different genes!

We even get a very small amount of genes from even more distant relatives. You share about 0.78% of your DNA with your great-great-great-great-great grandfather (aka 5th great-grandfather). So, even though it is very unlikely that your beard growing potential comes from your great-great-great-great-great grandfather – it is a possibility.

That is why siblings may sometimes have a very different appearance despite having the same mother and father.

If you want to know more about when your beard stops filling in, check out my other article – Road go through all of the data and science for answering this question in detail.

What age does your beard stop filling in?

Androgen insensitivity syndrome (AIS)

We talked above about how important it is that the hairs respond to DHT in the body. If the hair does not respond to the hormones produced from testosterone’s metabolism, the person may suffer androgen insensitivity syndrome. In this case, it is not the lack of testosterone but rather the insensitivity of the hair follicles to the testosterone and DHT.

An example of the effect of androgen insensitivity syndrome was presented in a 2009 study.  In this study, the authors looked at the effects of this syndrome on beards of sufferers.

The scientists looked at five different cases from the same family. They range from ages 21 up until 31. They all had a varying amount of beard, with one having a fully developed beard by the age of 19 whilst others had sparse hair coverage over the beard area.

This study highlights how complicated the genetics of beard growth is. The presence of a fully grown beard in one of the patients studied shows a wide spectrum of effects from having androgen insensitivity syndrome.

Does testosterone change as we age?

According to the UK’s national health system, puberty begins at about 12 for boys. But this is not when you can expect to see your first beard growth – it takes much longer than that!

The first signs of puberty are that the testicles get larger, and there will be a small amount of hair around the base of the penis. The testicles are where testosterone is produced and fuel your beard needs to grow thick and dense!

In the later stages of puberty (one to three years after initial signs), you will grow thicker body hair. The hair will go from a light, thin type to something much more substantial.

During puberty, testosterone increases in concentration around the body. Then, after the age of 30, there is a 1 to 2% decrease per year. Even though there is a slight reduction in testosterone every year, the compounding effects can mean that your testosterone is lowered by up to 20% by the age of 40.

As we talked about above, as long as testosterone is present at the early stages of puberty, it is likely that all of the hair follicles that would have turned into terminal hairs have already turned. The decrease of testosterone can affect the beard but, it will grow to some extent for the rest of the person’s life, even in the absence of testosterone.

How to increase beard growth and reduce patchiness

If you’re under 25 and have a patchy beard, don’t worry! Your beard has plenty of time to develop and connect.

Patchiness is a common problem with no one-size-fits-all answer. Not everyone can grow a thick, evenly distributed beard, and perfect coverage of beard hair is rare. If you talk to any bearded person, he will tell you about all the challenges they overcame to grow their current beard.

A beard with gaps will probably fill in a little if you are under 30. If you are in your 30s and still have gaps in your beard, you can do nothing to significantly increase the hair growth beyond more extreme interventions such as hair transplants and medications such as minoxidil.

If you want to know more about the proven ways to grow facial hair, you should check out my other article where I go through all of the quite detailed ways of increasing facial hair, including:

  • beard transplants
  • minoxidil
  • vitamin D
  • testosterone supplementation

Here are some of the things you can do if your beard has not filled in and you are concerned about it:

  • wait for six months – sometimes we are our worst enemies, and we are constantly obsessed with trimming up and shaping our beards. If you find that you are developing patchy areas, wait. In these six months, you will get to and understand whether or not you can cover up the patches with hair on either side of the patch or if your face needs a little bit of time to grow.
  • Choose a beard style that suits you – you should choose a beard style that suits your growth patterns. Remember to grow your beard and not someone else’s. Great beard styles lack the cheek area, moustache, sides, or cleverly use fades to cover up problem areas.
  • Keep it shorter in the troubled areas – if you have symmetrical trouble areas (for example, on your cheeks), you can cleverly use fades and short clippers to hide these issues behind a style.
  • Use the medication as a last resort – some people like to use products like minoxidil to develop their beard growth. Even though some people have significantly improved beard growth in certain areas of their face, this comes with potential side effects.

Following the above advice will make sure that you can grow a beard that you are proud of – remember that this may not be the beard you thought you would be able to grow. Part of this beard growing journey is to grow a beard by assessing the strong and weak points and choosing a beard style that matches that growth pattern.

For a full rundown of this information and more patchy beard advice, check out my YouTube video where I go through the top six insider tips for success:


In this article, we have looked at why a beard may be patchy and the effects of testosterone on beard growth.

There are many more steps to growing a beard from the moment testosterone is produced in the body than people think. There have to be three things that play together:

  1. the presence of testosterone – testosterone acts as a catalyst for producing a beard and, as soon as it is activated, the hair follicles of a beard can grow in the complete absence of it.
  2. Testosterone metabolised into DHT – DHT is much more likely to be the hormone that determines the thickness of your beard. DHT is produced from the metabolism of testosterone via an enzymatic process and acts on the base of hair follicles, turning them from light hairs into dark hairs.
  3. Androgen sensitive hair follicles – androgen sensitive hair follicles are hairs that respond to hormones. In the presence of DHT, these hairs turn from light hairs to dark hairs. Your genetics determines your sensitivity.

All of the above steps are predetermined by your genetics.

It is too simplistic to state that testosterone directly causes beard issues. There are studies that use testosterone to boost beard production in older men, but it is a very old study and has a very small sample size.

Follow the recommendations in this article to grow your beard faster and thicker – and I have even included some scientifically proven approaches which can help you grow a much thicker beard.

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!