Understanding hair loss

Understanding hair loss

Shedding some hair is completely normal. Even, the healthiest heads of hair will shed a little every day. This is because hair naturally grows over a cycle of growth, rest, fall and regrowth. We all should lose around 50 and 100 hairs a day, with each being replaced by a new hair growing in its place.

Problematic hair loss occurs when this natural cycling growth pattern is disrupted. A disrupted hair cycle leads to excess shedding, lack of growth and hair loss. Progressive hair loss, also called alopecia, is actually very common and can occur from a variety of root causes, including: changes in diet, stress, hormones, illness and medication, aging, autoimmune reactions and genetics – or combinations of these.

Our hair defines who we are and how we feel. Hair is the ROOT of our self-confidence. Have a bad hair day, have a bad day. Have a good hair day have a great day. There is no one that would ever say “I want bad hair”. Losing hair can be scary and can impact us in profound ways, but if you are losing hair or facing a hair challenge, you are not alone….

Close to 80% of men will experience hair loss in their lifetime, as will the majority of women. Hair loss can affect the old and the young, and men and women of all backgrounds, but despite it being so common, we know surprisingly little about what is really going on. Here at evolis, we are experts in hair science. Our research labs are the forefront of hair biology and hair cycle research. We’ve done all of the hard work digesting the science, separating fact from fiction and busting all of the myths about hair growth across the web.

So if you’ve noticed your hair falling out more than it used to, or if you are worried, we’ve got you covered. Our hair loss resource and information center should be your one stop shop for all questions on hair, scalp and skin.

Find out more about why your hair might be falling out.

So What Is Hair Anyway?
To understand hair loss, we first have to understand hair: what it’s made from and how it grows.

We can think of the hair as being made up of two distinct parts: The hair fiber and the hair follicle or root.

The Hair fiber is essentially made from dead cells (known as keratinocytes) that have filled themselves up with the protein keratin (keratinization) and have also connected themselves to the other cells around them with keratin.

So what is Keratin?

Keratin actually refers to a family of proteins whose role is to provide structure and rigidity in the body. There are 54 different types of keratin proteins. The main role of keratin is to provide strength and structure to the skin, nails, and hair, and also in many different cell types in the body. One of the reasons keratin is so strong is because it contains a high amounts of the sulfur containing amino acid cysteine (human hair is ~14% cysteine). The cysteine forms very strong cross links with other cysteine amino acids (known as disulfide bridges) which helps give keratin its rigidity and strength. When your hair is chemically treated, straightened or curled, you may notice an associated bad smell: this results from reduction of these sulfur bonds as the chemicals fundamentally change the internal structure of your hair shafts.

The hair fiber has three distinct layers. The majority of the hair fiber is represented by the elongated keratinized keratinocytes: These hair cells form the cortex. The cortex is surrounded by different keratinized cells which form the cuticle. Thick human hairs can have another cell type at their center which form a structure known as the medulla. This is not present in all hairs, but is sometimes found in terminal hair.



The follicles or roots are the living part of your hair. The hair follicles are actually organs, much like you would think of your heart or lungs. The follicles can be though of as little machines that make and control the growing hair shaft. Each hair follicle is independent and there are over a million of these organs all over the body, with 100 000 to 150 000 on the head. Like most other organs, hair follicles are made of different parts that do specific jobs.

Arrector pili muscle: small muscles that are attached to each hair follicle. Contraction of these makes hair stand up and forms ‘goosebumps’

Bulge region: region that contains the special hair follicle stem cells; very important cells that help regenerate the hair follicle in the hair cycle

Dermal Papilla: a region of special ‘mesenchymal’ cells and stem cells that acts as a control center for the follicle, controlling the hair cycle. At the top of the papilla is the pigmentary unit made of cells known as melanocytes that make the pigments that give hair its color

Epidermis: top layer of the skin

Follicular pore: The hole where hair shafts emerge. Multiple shafts may emerge from one pore in a ‘follicular unit’

Hair bulb: Club shaped region at bottom of hair follicle. Contains the germinal matrix which is comprised of cells that are changing to become the hair shaft

Hair Shaft: The hair fiber, composed of keratin. Cells known as keratinocytes grow from the base of the hair shaft and gradually harden with keratin. Hair grows as these cells are pushed up the channel by new cells being added in the germinal matrix

Inner root sheath: a layer of hardened cells that forms a channel for the growing hair

Outer root sheath: a region of special cells that surround the entire follicle. These cells are involved in signaling and respond to the environment outside the follicle

Pigment layer: layer of melanocyte cells that produce melanin in darker skin and in tanning

Sebaceous gland: A gland that makes sebum, an oil that lubricates the hair and scalp

Stratum corneum: the outermost layer of skin, made of cells that like the hair shaft, are hardened by the protein keratin

This process starts in the germinal matrix at the bottom of the follicle, as the hair stem cells begin to differentiate to keratinocytes (decide to become hair) and undergo keratinization. At this initial phase, special cells known as melanocytes transfer pigments to the keratinizing hair follicle giving the newly forming hair color. As new cells start to differentiate and divide at the bottom of the germinal matrix, they push the cells above them upwards and the shaft gradually gets longer. As hair cells move up the follicular channel, they elongate and gradually fill up with bundles and layers of filaments of keratin called fibrils. The cells also release keratin into the surrounding area. They eventually die and are locked in place in their cocoon of keratin becoming the hair fiber

The hair growth cycle

The individual hair follicles can be thought of as cycling, dynamic, independent mini-organs. That is, all hair follicles on the human head independently go through a cycle of growth, rest, shedding and regrowth that occurs many times throughout life. While in many animals like cats and dogs the hair cycle is seasonal and relatively synchronized, resulting in molting, the hair cycle in humans is not synchronized and hair follicles on your head will all be at different points in the hair cycle. This means that humans will shed about 100-120 scalp hairs a day, every day of the year.

The hair cycle has four distinct phases:

Anagen: The anagen phase is the growth phase of the hair where the hair fiber is growing and elongating. In a normal adult, about 80% of the follicles on the head will be in anagen at any given time. The anagen phase for scalp hair follicles usually lasts for between 5 and 7 years.

Catagen: In the catagen phase, the hair stops growing and goes through a process known as regression that lasts about 10 days. During regression, the dermal papilla detaches and the follicle shrinks. About 1% of the hair follicles on the head will be undergoing catagen.

Telogen: Telogen is the resting phase of the hair cycle where the follicles are relatively dormant for approximately 2 to 4 months. Approximately 9% of the hair follicles are in Telogen at any given time. During telogen, the stem cells from the bulge begin to organize with the population of stem cells around the remnant dermal papilla and a new hair begins to form.

Exogen: As a new hair is forming in the last part of the telogen phase, the old hair is gradually released and pushed out. This shedding of the old hair shaft to make way for a new one is known as exogen or sometimes kenogen.

Signaling in the hair cycle

The different stages in the hair cycle are directed by special molecules called growth factors, which we can think of as chemical signals. The quantity and mixture of these molecules in and around the hair follicle changes during the hair cycle, in a complex series of chemical conversations that control the pattern and stages of the hair cycle. In a nutshell, there are two main types of signaling molecules: positive regulators which tell the cells of the follicle to grow divide and produce the hair shaft, and negative regulators that tell the cells to stop growing and rest.

What Causes Hair Loss?
Hair loss is actually quite common, affecting the majority of us during our lifetime. There are a huge range of factors that can lead to hair loss, but all of these cause changes in the way hair grows, particularly the hair cycle.

The hair cycle is the center of hair growth, but it is also at the forefront in hair loss. The hair cycle has quite complicated physiology and biochemistry with a balance of positive and negative signals controlling the transition of each unique follicle through its own cycle in its own time. But, like anything complicated, it is very easy to upset the balance and get out of control.

Things like changes in diet, stress, hormones, and the aging process can upset the balance of signals in the hair cycle resulting in too many rest signals such as FGF5. What we see in almost all forms of hair loss and hair aging is shortening of the growth phase of the hair cycle. When the growth period becomes too short, hair falls out too quickly, excess shedding occurs, and the regenerating hair comes in finer and is less substantial. Unfortunately for some, follicles can become so dysfunctional that they no longer produce hair at all. Once you have reached this stage the only option is hair transplantation

At evolis our breakthrough technology revolves around one of the key players in the hair cycle hair cycle dysfunction and hair loss: a special molecule called fibroblast growth factor 5, or FGF5 for short. . FGF5 is what is known as a negative regulator of hair growth and is often referred to the “master regulator” of the hair cycle. The only job of FGF5 is to tell hair to stop growing and start resting. So too much FGF5 means that there is more hair fall, less hair growth, slower hair growth, and the growth of finer, less substantial hair. We also know of a FGF5 is hair specific, meaning it doesn’t have any other jobs in the body. Its only job is to signal hair to slow down, stop growing and start resting. The fact that FGF5 is hair specific means that it can be targeted without unwanted effects in other parts of the body. In fact, humans that naturally don’t have any FGF5 are healthy, but are just super hairy; with fast growing hair and amazingly long eyelashes!

We have also seen in a number of clinical studies, that treatment of the follicles by blocking FGF5 increases hair growth by up to 20%, reduces hair fall by about 80% and increases the proportion of happy, active follicles by close to 50%.

If you want to learn more, check out one of our more in-depth articles on:

How évolis Can Help
évolis Professional is the first treatment that actively targets the root of hair loss and hair aging by counteracting hair cycle shortening thought targeting FGF5.

The scientists at évolis Professional have developed technology aimed at repairing the hair growth cycle, targeting hair loss, preventing aging and maintaining the hair you have. The best thing is: évolis does this with natural botanical extracts, discovered scientifically and formulated specifically for tackling excess hair fall and promoting growth. As with anything we do we can back our products with sound scientific and clinical evidence.

As an added benefit, évolis is also infused with antioxidant and anti-inflammatory botanicals such as green tea, mangosteen, goji berries, rosemary and lavender, plus added vitamin C and E.

The unique évolis activator is a simple 30 second addition to any beauty or grooming routine: whenever you moisturize and whenever you brush your teeth, you should be looking after your follicles and ensuring they are growing the best hair they can

The hero of the unique range of hair loss products, anti-aging solutions and hair growth formulas evolis range are our activators or hair tonics. The évolis Activators are twice daily treatments that maintain follicle health. Any activator can be a simple 30 second addition to any daily beauty or grooming routine: whenever you moisturize, whenever you brush your teeth or style your hair, you should be looking after your follicles and ensuring they are growing the best hair they can. While the activators are going to work, the gentle évolis sulfate and silicone free shampoos are packed with botanicals to help maintain scalp health while conditioners and deep treatment masks look after the hair fibers, maintaining condition, fortifying and preventing breakage. Shop our unique range of hair loss products today.