Hair Growth Cycle: The Four Stages and What Shedding Means

What actually grows: the hair shaft or the follicle?

The part you can see is the hair shaft. It consists of keratinised cells and does not contain living cells that divide to make it longer. Growth comes from cells within the follicle beneath the skin, especially the matrix in the hair bulb.

The shaft has an outer cuticle of overlapping cells and a cortex that provides much of its strength and contains pigment. Some thicker hairs also have a central medulla. Damage to these structures can cause roughness, split ends or breakage without necessarily changing the follicle’s growth cycle.

The distinction matters when assessing a product: a conditioner may improve the feel and handling of the shaft, while treatment for a follicular disorder addresses a different problem. Both can be useful, but they do not do the same job.

The follicle is a living structure within the skin. Its dermal papilla helps regulate growth, and a stem-cell region called the bulge contributes to regeneration as it cycles. Nearby sebaceous glands produce sebum. The follicle remains in the scalp when a hair is naturally shed, ready to participate in further growth cycles if healthy.

The four stages of the hair growth cycle

1. Anagen: active growth

During anagen, cells in the hair bulb divide and contribute to the developing shaft. Scalp hairs can remain in this growth phase for several years, much longer than hairs at some other body sites. This helps explain why scalp hair can grow longer than eyebrow hair.

Most scalp follicles are normally in anagen at any one time. A commonly used estimate is around 80–90%, although measurements differ between populations and methods. Growth averages roughly a centimetre a month, with variation between individuals and scalp regions.

The duration of anagen affects potential length, but length also depends on cutting and breakage. Hair that seems unable to grow beyond a certain point is not necessarily growing slowly at the root; its ends may be breaking as new length is produced.

2. Catagen: transition and regression

Catagen is the brief transition after active growth, usually lasting a few weeks. The lower part of the follicle regresses through a controlled biological process, and a fully keratinised club hair forms.

Only a small proportion of scalp follicles are in this phase at once. Regression of the lower follicle is a normal part of cycling; it does not mean the entire follicle has been permanently destroyed.

3. Telogen: rest and retention

In telogen, the retained hair no longer lengthens. This resting phase commonly lasts a few months on the scalp. The follicle remains biologically capable of entering another growth phase, so “resting” should not be understood as “dead”.

The old hair may stay attached for a time before release. This delay is important in telogen effluvium: a trigger can change the cycle now, while the extra shedding becomes noticeable only later.

4. Exogen: release of the old hair

Exogen describes shedding of the old shaft from the follicle. It is often discussed separately from telogen because retention and release are different events. The release can overlap with new growth rather than functioning as a perfectly isolated fourth block on a timetable.

The illustration above shows the three traditional growth, transition and resting phases. Exogen adds the separate process of hair release. Both ways of describing the cycle appear in educational material; recognising the shedding process makes the explanation more complete.

A pale club-shaped end on a naturally shed hair does not mean that the whole follicle has come out. The living structure remains within the skin. Repeatedly examining every shed hair is unlikely to establish a diagnosis, however; changes in scalp density and clinical examination are more informative.

What can change the hair cycle?

Hormones and changes in health

Hormonal signals influence follicular activity. DHT contributes to shorter growth phases and miniaturisation in susceptible scalp follicles, while thyroid disorders can be associated with diffuse shedding. These effects do not mean that every person with hair loss needs the same hormone tests.

A DHT test measures a blood concentration, not the timing of each follicle. If a test is proposed, ask which clinical question it will answer. Our guide to DHT and hair loss explains the difference between circulating hormone levels and follicular sensitivity.

Pregnancy can change the balance of growing and resting hairs. After childbirth, increased shedding may occur as more hairs move through the cycle together. This postpartum shedding is often temporary, but persistent loss or other symptoms should still be assessed rather than automatically attributed to childbirth.

Genetics and ageing

Inherited characteristics influence hair texture, diameter, growth behaviour and susceptibility to pattern thinning. Having a relative with hair loss does not establish the exact future course for another family member.

Hair density and growth characteristics can change with age. A new patch or a rapid change still warrants assessment, whatever your age.

Nutrition, illness and stress

Significant illness, rapid weight loss, restrictive diets and certain deficiencies can contribute to changes in the cycle. Adequate nutrition is important, but taking extra vitamins without a relevant deficiency does not reliably make follicles grow faster or remain in anagen longer.

Stress can be associated with shedding, but the relationship is not a simple switch that you can turn off by relaxing. If loss is persistent, seek assessment for other contributing factors as well. Support for distress can be valuable alongside investigation of the hair itself.

Hair care and breakage

Heat, chemical processing and rough handling can damage the shaft. Tight hairstyles can also exert repeated tension on follicles. These mechanisms should be distinguished from a change in growth-cycle timing.

A useful clue is whether you are seeing full-length shed hairs or many shorter broken pieces, although both can occur together. Gentle detangling, reducing excessive heat and avoiding painful tension can help protect existing hair. They do not replace treatment of an inflammatory or infectious scalp condition.

Why does shedding start months after a trigger?

Telogen effluvium

Telogen effluvium is increased diffuse shedding associated with more follicles entering the resting phase. It often becomes noticeable about two to three months after a trigger, such as a significant fever, surgery, childbirth or marked dietary restriction.

For example, an illness in January may be relevant to shedding that starts in March. The delay can make the two events seem unrelated. A consultation therefore considers the preceding months, not just what happened in the week the hair started falling out.

Identifying and addressing a trigger can help recovery, but the visible density does not return overnight. Shedding may settle before shorter regrowing hairs contribute enough length to improve coverage. Episodes lasting more than six months are described as chronic telogen effluvium and may involve continuing or repeated triggers.

Pattern thinning can occur alongside shedding

In androgenetic alopecia, progressive miniaturisation means follicles produce finer, shorter hairs. It commonly causes recession and crown thinning in men, or a widening parting in women. It is not simply a temporary synchronisation of otherwise healthy follicles.

A person can have pattern thinning and a separate telogen effluvium episode. Increased shedding may make underlying density changes more noticeable. This is one reason why counting hairs alone cannot establish the cause or predict recovery.

Anagen effluvium

Some treatments, particularly certain chemotherapy regimens, can interrupt the rapidly dividing cells involved in active hair production. This can cause much faster hair loss than the delayed pattern of telogen effluvium.

The extent and timing depend on the treatment, and recovery varies. Many people experience regrowth afterwards, but it should not be promised on a universal schedule. The treating team can explain the likely effects of a particular regimen and discuss appropriate support. Do not change an essential medicine without speaking to the prescriber.

What happens to the cycle after a hair transplant?

A transplant moves existing follicles into a new area of scalp. It does not make hair grow immediately at full density. The early appearance of the short implanted shafts and the eventual growth of new hairs are different stages of recovery.

Some transplanted shafts commonly shed in the weeks after surgery while the follicles remain in place. Temporary shedding can also affect existing native hair around the procedure, often called shock loss. The amount varies, and not every patient follows the same course.

New growth often becomes noticeable from around three to four months, with further improvement over subsequent months. NHS guidance describes full results developing over roughly ten to eighteen months. This reflects the gradual regrowth and maturation of individual hairs.

A hair transplant consultation should include realistic timelines, donor-area assessment, possible continued loss of native hair and written aftercare. Hair shedding alone is not proof that a transplant has failed, but pain, spreading redness, discharge or other unexpected changes should be discussed promptly with the clinic.

Follow the surgical team’s instructions for washing and protecting the grafts. Our guide to hair care after a transplant explains the practical stages of recovery. A biological timeline is background information, not a substitute for individual postoperative advice.

How much shedding is normal, and when should you seek advice?

Around 50–100 shed hairs per day is a commonly quoted range. The number you see at one time changes with washing frequency, brushing and how easily shed hairs remain caught in the hairstyle. A single large wash-day collection does not automatically prove excessive loss.

More useful warning signs include a persistently widening parting, reduced density, new bare patches or a sustained change from your usual shedding pattern. Seek advice about scalp soreness, burning, significant scaling or inflammation. A GP can review the history and decide whether examination, selected tests or dermatology referral would help.

To prepare for an appointment, note when you first noticed the change, whether it is diffuse or patchy, relevant illnesses and medication changes, and any dietary restriction or recent childbirth. Photographs taken under similar conditions can show progression. Mention the emotional impact too; support is appropriate even while the cause is being investigated.

Supporting recovery and setting realistic expectations

Choose a manageable routine that protects the shaft and keeps the scalp comfortable. Avoid painful tension, use heat carefully and maintain a balanced diet. Supplements should address a clear need rather than promise to “reset” every follicle. Treatment for a diagnosed condition should have an agreed review point, since meaningful change usually needs time.

If you are planning surgery through Body Expert, the standard support includes an English-speaking coordinator and 12 months of postoperative follow-up. The standard package includes a five-star hotel with breakfast and VIP airport, hotel and clinic transfers. Flights and PRP are not included; the personalised quote should detail any additional services.

Ask the clinical team what is expected at each review and which symptoms require earlier contact. A realistic plan makes room for individual variation, assesses both growth and scalp health, and explains what to do if progress differs from expectations.

Common questions about the hair cycle

Does cutting or shaving hair change the cycle?

Cutting affects the visible shaft, not the follicle’s internal growth programme. A blunt cut end may feel thicker as it grows out, but shaving does not create more follicles or cure miniaturisation.

Can washing make hair fall out prematurely?

Washing can release hairs that were already ready to shed, making them more noticeable. Gentle cleansing does not mean the whole follicle is being washed away. Rough handling can contribute to breakage, while an inflamed or painful scalp needs its own assessment.

Does a white end on a shed hair mean it cannot regrow?

A pale club-shaped end can be part of normal shedding. It is not the entire living follicle. The outlook depends on the condition affecting the scalp, rather than the appearance of one shed hair.

Can you force all hair into anagen?

Normal hair density depends on ongoing cycling, not permanent synchronisation of every follicle. Some treatments influence growth in specific disorders, but a promise to switch all hair into anagen or permanently stop normal shedding should be treated cautiously.

Sources

Natarelli, N., Gahoonia, N., & Sivamani, R. K. (2023). Integrative and mechanistic approach to the hair growth cycle and hair loss. Journal of Clinical Medicine, 12(3), 893. Read source

Hoover, E., Alhajj, M., & Flores, J. L. (2023, July 30). Physiology, hair. In StatPearls. StatPearls Publishing. Read source

Asghar, F., Shamim, N., Farooque, U., Sheikh, H., & Aqeel, R. (2020). Telogen effluvium: A review of the literature. Cureus, 12(5), e8320. Read source

Almohanna, H. M., Ahmed, A. A., Tsatalis, J. P., & Tosti, A. (2019). The role of vitamins and minerals in hair loss: A review. Dermatology and Therapy, 9(1), 51–70. Read source

Goldin, J., Zito, P. M., & Raggio, B. S. (2025, August 2). Hair transplantation. In StatPearls. StatPearls Publishing. Read source

National Health Service. (2023, September 29). Hair transplant. Read source

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