Hair Growth Explained: The Science and How to Stimulate it

Every guy has his own personal hair growth journey, whether it be the pattern of hair growth on his head or the speed at which his facial hair grows.

Despite the fact that nearly all of us experience changes in hair growth, and even hair loss, at some point in our lives, many people don’t actually know how these processes work. 

Hair Follicles Explained

Unsurprisingly, hair follicles exist so that we can grow hair. On average, we have about 10,000 of these just on our head. 

Follicles produce hair over and over again in cycles (which we’ll explain in more detail below.)

The Hair Growth Cycle

Each hair follicle naturally goes through three stages throughout its lifecycle, from growing to shedding.  

We’ve outlined the details of each of these stages clearly below.


This is your hair’s growth phase. After our hair follicles have been nourished from our blood supply, hair growth begins. 

This initial phase can last anywhere between three to five years, and it determines how long our hair can grow. During the Anagen phase, hair grows about 1 cm every 28 days.


After Anagen comes Catagen. During this phase, hairs shrink and detach from the blood supply, which causes them to lose access to nutrients and stop growing. 

Also known as the transition phase, Catagen is much shorter than Anagen, lasting only up to ten days.


Also known as the resting phase, during this stage the old hair on the scalp begins to rest while new hairs start to grow underneath them. This can last for around three months.

It is also during this phase that the old hair eventually detaches from the hair follicle. When you wash your hair or create some other kind of movement around the hair follicle, these resting hairs will fall out.

Which Factors Affect Hair Follicles and Hair Growth?

There are several factors that can affect the hair growth cycle and determine the speed at which it occurs. 

It is worth remembering that hair follicles do not simply disappear in those who experience hair loss – although hair follicles do eventually die, this takes a long time and hair follicles generally remain on your scalp long after your hair is lost.

Hair follicles have a long life cycle, and continue to reproduce hair on your scalp for decades. However, over time this is affected by other processes which cause less hair to grow on your scalp.

For example, many men will start experiencing Male Pattern Baldness at some point in their life. This can be caused by a number of factors, but is typically caused by Dihydrotestosterone (DHT), a male hormone which leads to hair loss. 

During this process, your hair follicles actually change size which affects the thickness of your hair.

Why Does Hair Grow Fast and Slow?

You have no doubt noticed that some people’s hair seems to grow far quicker than others. The speed at which your hair grows is determined by a number of factors, and this is why it can vary so much between different people. 

On average, hair grows between 0.5cm and 1.7cm per month.If you want to improve the rate at which you see healthy hair growing on your scalp, it’s worth improving the overall health of your hair. 

Aspects of your lifestyle can have an effect on the health of your hair. We’ll go into more detail about these below.

Stimulating Hair Growth and Improving Hair Health


Hair health can be largely affected by your nutrition – low iron levels can lead to slower hair growth, for example. Iron can be found in many green vegetables and supplements. Zinc and vitamin B12 also help improve overall hair health.

Getting more sleep

It may sound silly, but missing sleep can have a lot of knock-on effects when it comes to your health, including your hair. 

Losing sleep can cause higher stress levels, which in turn can have a negative effect on hair growth.

Minimizing your stress levels has been shown to help prevent some forms of hair loss, although this is not always sufficient, as genetics typically plays more of a role. 

If you’re wondering whether stress is playing havoc on your hairline, check out our article on it.  

Staying hydrated

Getting enough water is essential for lots of different bodily functions, and hair growth is no different. 

Water helps transport nutrients throughout your body, and as mentioned earlier, these nutrients can have a positive effect on your overall hair health.

How to Deal with Hair Loss

Hair loss generally refers to a loss of hair on your head, but can also mean a loss of hair from anywhere on your body. 

While there are different forms of hair loss, the most commonly experienced form of hair loss in men is Male Pattern Baldness (MPB). 

Also known as Androgenetic Alopecia, MPB is extremely common and affects around two-thirds of men by the age of 35. However, there are effective ways of treating this form of hair loss. 

What Causes Hair Loss?

There are many reasons that men experience hair loss, and these can range from genetics to lifestyle and nutrition. 

One of the primary causes of hair loss amongst men is DHT, a byproduct of testosterone in your body. This is essential for men’s development during puberty, but also one of the main causes of hair loss.

Treatments for Hair Loss

There are hair loss treatments available which work to combat the effects of DHT or block its production. 

Finasteride, an effective hair loss treatment for men, lowers the levels of DHT in your scalp, which can, in turn, reverse the balding process and prevent further hair loss.

What haircut should I get?

Discover which haircut you should get for your face shape

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment or medication.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment or medication.

Hair loss treatment for a long term solution

Clinically approved options available

Thousands of happy customers

Get started