Why Am I Shedding So Much Hair? Chronic Telogen Effluvium Explained

Hair shedding, it happens, totally normal.  But then you notice, a bit more in the shower, a bit more on the pillow, then a little bit more left in the brush every day.  At first it’s a little concerning, but it’s probably fine, maybe that’s what 100 hairs look like.  A year later, it feels like it’s a bit worse.  Then you start to see it in your reflection.  Flatter roots, a thinner ponytail and see-through ends.  Google says it is telogen effluvium, your doctor says your blood tests are normal, and ChatGPT throws you a confident diagnosis after a few probing questions and three self-conscious hair selfies: chronic telogen effluvium.

Ok, but how?  Why? And what now?  

The name telogen effluvium is derived from Greek and Latin: telogen refers to the resting stage of the hair growth cycle and effluvium means a flowing out. In most cases, telogen effluvium is acute, meaning it develops after a distinct internal or external trigger, such as illness, a period of sustained stress, a new diet, medication change, or hormonal shift.  Acute telogen effluvium will usually resolve within 3 to 6 months once the underlying trigger has been resolved.  

Chronic telogen effluvium is different. In chronic telogen effluvium, excessive shedding persists for more than six months, often fluctuates over time, and usually reflects persistent, overlapping, or recurrent internal and external pressures that prevent the follicle from completing a stable, efficient growth cycle capable of producing a thick, healthy hair fibre that grows to its genetic length potential.  Chronic telogen effluvium is not a single prolonged shedding event, but a long-term disturbance of the hair growth cycle, driven by multiple contributing factors.

The hair growth cycle

The hair follicle cycles continuously through phases of growth, transition, rest, and shedding, before starting the process again.

Generally, the hair growth cycle is a sequence of four successive phases:  

• a hair growth phase (anagen)

• a transition phase (catagen) 

• a resting phase (telogen), and then

• a shedding phase (exogen)

In chronic telogen effluvium, the anagen phase is shortened, meaning hairs do not remain in active growth for as long as they should.  As a result, a greater proportion of follicles accumulate in telogen at the same time. Adhesion machinery that should support hair fibre anchorage whilst in telogen fails, which significantly increases the number of hairs shed alongside the number of hairs normally lost during exogen.

Factors that increase anagen to telogen transition and shedding

At a molecular level, factors such as loss of hair fibre adhesion mechanisms, reduced growth factor signalling, changes in the extracellular matrix within the dermis, bacterial biofilm development, poor blood flow, and micronutrient insufficiencies can combine to disrupt the conditions needed for a normal hair growth cycle.  The involvement of multiple pathways and drivers demonstrates the complexity of chronic telogen effluvium development and helps explain why it can be difficult to resolve when the underlying contributors are not properly identified.

1. The anagen phase becomes shorter

Anagen is the growth phase of the cycle, where keratin cells of the hair follicle are dividing rapidly and growing, pushing upwards from the base of the follicle and travelling up the hair follicle canal to what we eventually see as the growing hair fibre emerging from the scalp.   

A number of internal and local scalp-level pressures can shorten the anagen phase. Inflammation, oxidative stress, reduced growth factor signalling, poor nutrient availability, altered extracellular matrix support, microbial imbalance, barrier disruption, and poor blood flow can all weaken the conditions needed to keep the follicle in active growth. Instead of remaining in anagen for long enough to produce a thicker, longer fibre, the follicle transitions out of growth too early and enters telogen prematurely.

When anagen is shortened, the hair has less time to fully develop. The immature fibre will be shorter, finer, and have lower tensile strength and thermal resistance. At the same time, more follicles are pushed into the telogen phase, increasing the proportion of hairs detached from any blood supply and setting the stage for noticeable shedding.

2. Breakdown of hair follicle adhesion machinery

During the telogen phase, the hair has fully detached from its blood supply and from the base of the follicle, yet the fibre remains anchored within the follicle through specialised adhesion proteins.  These proteins help keep the hair securely in place during the resting phase, preventing it from being shed too early. 

Key adhesion proteins that anchor the hair in telogen include desmoglein 3 and collagen 17. Although both support hair retention, they do so in different ways. Desmoglein 3 mainly supports lateral, cell-to-cell adhesion, helping the telogen hair remain mechanically connected to the hair follicle lining.  Collagen 17 is a transmembrane protein found at the base of the hair follicle. It helps anchor the cells at the bottom of the follicle.  In simple terms, desmoglein 3 helps hair follicle cells hold together sideways, while collagen 17 helps anchor them downward.  

When the timing is right, cells lining the follicle release specialised proteases, which are enzymes that break down adhesion proteins.  These proteases break the anchoring attachments so the hair can be released in the final shedding phase, known as exogen.

With chronic telogen effluvium, this precise shedding system is disturbed before exogen is supposed to occur. Mechanical stress, inflammation, oxidative stress, barrier disruption, and microbial overgrowth all destabilise the adhesion environment and increase premature hair release. Inflammation and oxidative stress weaken follicle integrity, while rising protease activity can begin to dismantle adhesive proteins too early.  Proteases released by S. epidermidis have been shown to degrade desmoglein proteins, while proteases released by neutrophils break down collagen 17 in an inflamed, dysbiotic environment.

3. Dermal Structure

The dermis is the deeper connective tissue layer of the scalp, lying beneath the surface skin and surrounding the lower portion of the hair follicle. Within it sits the extracellular matrix, the structural framework that surrounds and supports the cells. Together, they create the living support environment that gives the follicle its mechanical stability, blood supply, and tissue architecture needed for healthy cycling and strong hair growth.

The key structural components of the dermis are:

• Collagen, especially type I and III, which gives tensile strength

• Elastic fibres, which give elasticity and flexibility

• Proteoglycans and glycosaminoglycans, which help with hydration, spacing, and matrix organisation

• Fibroblasts, which build, maintain, remodel the extracellular matrix 

The scalp extracellular matrix is a living connective tissue framework maintained largely by fibroblasts. It provides follicle structural support, helps organise the surrounding dermal environment, and acts as a local reservoir for growth factors such as epidermal growth factor and fibroblast growth factor. These signals help influence stem cell activity, follicular behaviour, and the development of a normal hair fibre.

Fibroblasts are highly sensitive to oxygen availability, inflammation, pH, oxidative stress, hydration, and nutrient status.  Changes in the wider tissue environment can quickly affect how well this system functions. When fibroblast activity declines, matrix turnover becomes less efficient and the supportive architecture around the follicle begins to deteriorate. If that environment becomes thinner, more fibrotic, or structurally disordered, the follicle becomes less able to regenerate fully with each new anagen cycle. Over time, it may sit more superficially, produce weaker fibres, and become progressively less productive.

Hair fibres produced in this environment are not fully developed by the time they emerge from the scalp.  They have a reduced shaft diameter, shorter length and a greater tendency towards breakage. 

4. Blood vessel maintenance 

The extracellular matrix plays an important role in blood vessel function by providing structural support, regulating growth factor availability, and influencing cell signalling. In doing so, it helps determine how easily microvessels can form, stabilise, and perfuse the surrounding tissue.

This vascular network is essential to the follicular environment, not only for delivering oxygen, glucose, amino acids, hormones, and key micronutrients such as iron, zinc, and folate, but also for clearing carbon dioxide, metabolic by-products, and inflammatory waste. Without efficient microvascular support, the follicle becomes harder to nourish, to regulate, and to maintain in a stable growth phase.

5. Micronutrient insufficiency 

Micronutrient insufficiency can disrupt the hair growth cycle from several directions at once. A person does not need to be frankly deficient for a micronutrient issue to affect the hair. In some cases, a level may still fall within the laboratory reference range, yet remain insufficient to fully support follicle function.  This is why women with chronic telogen effluvium often report ‘normal’ blood test results.

Individual functions of various micronutrients in relation to the extracellular matrix:

Iron is required for energy production and maintaining a well-oxygenated follicular environment. In low iron states, lower oxygen availability alters fibroblast activity, weakens normal extracellular matrix maintenance, and creates conditions that allow biofilm formation, particularly when inflammation or barrier disruption is already present.

Folate is required for normal fibroblast function. When folate levels are low, fibroblasts show reduced function, leading to decreased collagen processing and decreased production of substances like proteoglycans and elastin.

Magnesium supports fibroblast activity, collagen cross-linking and extracellular matrix stability, which are crucial for the completion of a normal hair growth cycle.  Magnesium also regulates calcium balance and calcium requires magnesium for proper utilisation of calcium dependent adhesion molecules like desmoglein-3 to prevent premature shedding of telogen hair.  

Copper is needed for lysyl oxidase activity, which helps cross-link collagen and elastin, giving the extracellular matrix its strength and stability. It also plays a role in blood vessel development. 

Zinc preserves hair follicle stability by supporting fibroblast activity, tissue repair, antioxidant defence, and  limiting excess protease-driven premature release of the hair follicle.

Calcium is required for desmoglein 3, the adhesion molecule (responsible for cell-to-cell adhesion of the hair follicle), because cadherins are calcium-dependent adhesion molecules.

Summary - Hair loss doesn’t just happen

Chronic telogen effluvium reflects a hair follicle cycling in a biologically compromised environment. The hair growth cycle depends on stable growth signalling, healthy dermal support, adequate nutrient delivery, sufficient blood flow, effective adhesion machinery, and a scalp environment capable of supporting proper regeneration. 

When hair fibre adhesion is weak, bacterial biofilm persists, nutrient delivery is poor, and the hair follicle is no longer able to sit deep within the dermis, the follicle becomes less able to sustain a strong anagen phase. Hairs are pushed prematurely into telogen, retained less securely, and shed earlier than they should. Re-entry into a new anagen phase may then be delayed, and over time the replacement hairs become thinner and shorter.

There is no standard cure for chronic shedding because the drivers vary from person to person, which is why proper investigation, targeted treatment, and long-term follow-up matter. Chronic telogen effluvium is often reversible because the follicle is not permanently destroyed, but recovery can be slow, especially when the condition has persisted for years or is occurring alongside early miniaturisation. 

Whilst topicals and injectables such as minoxidil, mesotherapy, and PRP may support regrowth, the most effective approach is usually more holistic: identifying and correcting the biological pressures affecting the follicle, reducing scalp inflammation, improving the extracellular matrix, supporting a healthy scalp microbiome, resolving nutrient insufficiencies, and working within a structured support programme with a trichologist.