Hair cycle



The stages of hair growth help better understand how hair grows and what might be done to prevent or treat premature hair loss.

In fact, the first three phases — anagen, catagen, and telogen — cover the growth and maturation of hair and the activity of the hair follicles that produce individual hairs. During the final phase, exogen, some hair sheds, but usually, new hairs are getting ready to take their place.

Each phase has its own timeline, which can be affected by age, nutrition, and overall health. Therefore, a healthy lifestyle, limiting stress, proper diet, and gentle hair care can help promote healthy hair growth for a long time.

If you believe that you’re losing your hair at a faster rate than you’re used to, book a consultation (£50 that can be redeemed against the treatment) at Nar London. An underlying condition that is disrupting the cycle of hair growth may be to blame, and treating it promptly may help slow hair loss and preserve the healthy hair you have left. Moreover, it is also possible to stimulate the growth of dormant hair follicles with non-invasive hair loss treatments such as PRP, PRF, and Mesotherapy for hair.

How Does Hair Grow?

To understand how hair grows, we first need to look at its parts. Hair is made up of two parts: the follicle and the shaft.

The shaft grows from the follicle, which is the root of the hair located beneath the skin. Indeed, there are approximately 100,000 hair follicles on the scalp and around five million hair follicles on the body.

The hair follicle itself is made up of the papilla and the bulb. The papilla contains tiny blood vessels that deliver blood supply to the hair follicle. The papilla nourishes the hair follicle with the necessary nutrients for hair growth. The bulb, which surrounds the papilla, is where the hair cells divide.

The hair shaft is the visible part of the hair. The hair shaft is made up of a hard protein called keratin and a scale-like outer protective layer called the cuticle. Hair shafts are actually dead, which is why it is important to take care of your scalp when buying the right shampoo.

The Hair Cycle

As new hair is created in the follicle, it pushes out the hair shaft, creating longer-looking hair. Typically, hair grows about 0.3mm to 0.4mm each day. Thankfully, not all hair follicles are growing new hair at the same time. Hair growth occurs in a cycle. At any given time, each strand is in a different part of the cycle. Otherwise, they would shed at the same time and we would be bald like a tree in autumn!

Let’s have a look at the different phases in the hair cycle:

1. Anagen: Growing phase 

To start, the stages of hair growth begin with the anagen phase and this is the longest phase, lasting about 2 to 6 years.

During the anagen phase, your hair follicles are pushing out hairs that will continue to grow  (about half an inch each month) until they are cut or reach the end of their lifespan and simply fall out.

Also, note that at any time, about 85/90% of the hair follicles on your scalp are in the anagen phase.

2. Catagen: Transition phase

Subsequently, the catagen phase starts when the anagen phase ends, and tends to last about 10 days or so.

During this cycle, hair follicles shrink and hair growth slows. The hair also separates from the bottom of the hair follicle, yet remains in place during its final days of growing.

Only about 5 percent of the hair follicles on your scalp are in the catagen phase at any given time.

3. Telogen: Resting phase 

Then, the telogen phase typically lasts around 3 months. It is estimated that 10 to 15 percent of your hair follicles are in this phase.

This phase is also called “resting” because the hairs don’t grow during the telogen phase, but they don’t usually fall out either. The telogen phase is also when new hairs start to form in follicles that have just released hairs during the catagen phase.

Many experts consider the telogen phase the shedding phase, as well, but many scientists have divided this stage into two parts: the telogen and exogen stages.

4. Exogen: Shedding phase 

Finally, the exogen phase is essentially a “continuity” of the telogen stage of hair growth. During the exogen phase, hair is shed but losing 50 to 100 hairs per day is normal.

This cycle can last about 2 to 5 months, new hair follicles are growing, and “older” hairs fall away.

Structure Of Hair

Your hair structure can be divided into two parts:

1. The structure inside the follicle.

2. And, the structure of the hair shaft that is present above the epidermis.


1. Structure Inside Follicle

A. Hair Bulb

It is the lowest part of your hair strand, which lies inside the follicle. The club shape of the hair bulb helps it to get locked by the dermal papilla.

B. Dermal Papilla

It is the cone-shaped elevation that is present at the base of your hair follicle. It fits into the hair bulb and holds it. The dermal papilla is connected with the blood vessels.

C. Arrector Pili Muscle

It is an involuntary muscle present at the base of the hair follicle. You get goosebumps when arrector pili contracts.

D. Sebaceous Glands

These are the oil glands that are connected to the hair follicles. Sebaceous glands secrete sebum for your hair.

2. Structure Of Hair Shaft

A. Cuticle

It is the outermost layer of your hair strand. It acts as a protecting layer to the inner hair structure. A strong and integrated cuticle layer imparts shine to your hair.

B. Cortex

It is the middle layer of the hair strand. The protein present in the cortex is responsible for the elasticity and color of your hair.

C. Medulla

It is the innermost layer in the hair strand. In general, it exists only in thick and coarse hairs. The purpose of the medulla has not been identified yet.

Diet & nutrition

Having a healthy diet is important. Your body and hair follicles need a healthy balance of vitamins, iron, fiber, and protein as this helps regulate your Hair Growth Cycle. We also recommend incorporating tailored nutritional supplements into your daily routine. You can have food intolerance tests and other blood tests to better understand what you should eat and what you should avoid eating.

Stress & Hair loss

Excessive and sustained stress has a negative impact on your health. Stress can increase the ‘resting’ phases of the cycle where new hairs are not growing. Try to manage your stress as there are techniques and lifestyle changes that can help you.

Types of stress-related hair loss

There are three main types of hair loss associated with excessive levels of stress i.e. telogen effluvium, trichotillomania, and alopecia areata.

  • Telogen effluvium

As we have seen hair follicles undergo stages of growth i.e the anagen phase,  the catagen phase, and the telogen stage. Most hair follicles are in the anagen phase. However, a severe shock or stress can accelerate a number of hair follicles into the telogen stage of hair growth. This phenomenon is called telogen effluvium.

In fact, within 3 months of the stressful event, an excessive amount of hair can fall out. This can be even more distressing for the person experiencing telogen effluvium.

Also, for some women, the stress and even trauma in giving birth trigger telogen effluvium in up to 90% of postpartum cases. Other causes can include severe stress, surgery, high fever, certain medication, and intense diet.

  • Trichotillomania

Trichotillomania is an impulse control disorder where you have an urge to pull the hair out from your head, eyebrows, eyelashes, and other parts of your body.

A number of factors may trigger it, like boredom, frustration, loneliness, or stress. In this case, you don’t just feel stressed, but you feel an irresistible urge to pull out your own hair because of your stress.

  • Alopecia areata

Alopecia areata is an autoimmune condition where your body attacks its own hair follicles. With autoimmune disorders, your body’s immune system does not work properly. Even worse, it attacks its own cells, causing varying symptoms and diseases. And in our case, this leads to substantial hair loss. However, the patches in AA usually grow back in 3 to 6 months without any treatment.



No matter your age, a receding hairline, hair loss, or thinning hair can affect you emotionally and even undermine your confidence.

If you are concerned about hair loss or are considering hair restoration treatments we can offer advice and help to find the most suitable treatment course for you.

Nar London located in Harley Street, London is a leader in Hair Loss and non-invasive Hair Restoration treatments. Book a  consultation or directly book your treatment online.