A hair growth cycle diagram shows the four stages every follicle moves through, over and over, for your whole life: anagen, the growth phase lasting several years; catagen, a transition of a few weeks; telogen, a resting phase where roughly 10 to 15 percent of your hairs sit at any moment; and exogen, the release of the old hair. Your follicles run this cycle independently, which is why you shed daily instead of moulting.

What does a hair growth cycle diagram actually show?

Most versions of the diagram show a loop rather than a line, and that loop is the important idea. A follicle does not grow one hair and retire. It grows a hair, dismantles the growing machinery, rests, releases the old shaft, and rebuilds to start again. A healthy follicle repeats this roughly ten to thirty times across a lifetime.

Here is the cycle laid out with the numbers attached, which is what most published versions leave off.

Stage 1: what happens during anagen?

Anagen is the active growth phase, and it is the only one that makes a hair longer. The follicle takes on a deep, onion like shape, cells at the base divide rapidly, and they keratinise into the shaft that emerges from the scalp. Scalp anagen typically runs two to seven years, and hair grows at roughly a centimetre a month.

That duration is the reason people have such different maximum lengths. Someone with a seven year anagen can grow hair to the waist. Someone with a two year anagen will find their hair stops at the shoulders no matter what they do, because each strand is released before it can get longer. This is genetic, and no product changes it.

There is also a hard biological ceiling. The cells that drive growth can only divide a limited number of times, and that limit is part of what sets how long anagen lasts before catagen begins. Eyebrow and eyelash follicles have a very short anagen, measured in weeks, which is why they never need cutting.

Stage 2: what happens during catagen?

Catagen is the shortest phase and the least discussed, lasting around two to three weeks. The follicle transitions into quiescence: the lower portion shrinks, the hair detaches from the dermal papilla that supplied it, and the blood supply withdraws. Growth stops.

The hair is not shed at this point. It is converted into a club hair, a fully keratinised shaft with a small white bulb at the root, and it stays anchored in place while the follicle regresses beneath it. Only about one percent of your hairs are in catagen at any moment, which is why you will never notice it happening.

Stage 3: what happens during telogen and exogen?

Telogen is the resting phase. The follicle is dormant, the shaft is not growing, and the club hair simply sits there. It lasts roughly three months, and at any given time about 10 to 15 percent of the hairs on your head are in it.

Exogen is the release, and it overlaps with the end of telogen. The old club hair detaches and falls, usually while you wash or brush, and a new anagen hair is often already pushing up beneath it. Fifty to a hundred hairs a day is the normal range. Those hairs in your brush are not a loss, they are the visible end of a process that started years ago.

The distinction matters enormously when something goes wrong. A body stress can push an unusually large number of follicles out of anagen and into telogen at the same time. Because telogen lasts about three months, the shed does not appear until two to three months after the event that caused it, which is why almost nobody connects the two. That is telogen effluvium, and it recovers.

The cycle at a glance

The same information as the hair growth cycle diagram above, in table form for quick reference.

Why is every hair on a different schedule?

One thing a hair growth cycle diagram cannot show is that your follicles are not synchronised. Human hair cycling is asynchronous, meaning each follicle keeps its own clock rather than moving in step with its neighbours. Many mammals do the opposite and moult seasonally, shedding a coat in one coordinated wave.

Asynchrony is why you always have hair. It also explains why thinning creeps up on people. If ninety percent of your follicles are growing and a few percent are resting at any moment, a gradual shift in that balance shows up as slowly reducing density rather than a dramatic event, and by the time it is obvious in the mirror the change has usually been under way for a while.

It is also why the mirror is a poor instrument for tracking this. Consistent monthly photographs in the same light, at the same parting, will tell you far more than a daily inspection.

What can disrupt the hair growth cycle?

Almost everything that goes wrong shows up at one point on the hair growth cycle diagram: the exit from anagen. Most disruption works by pulling follicles out of anagen prematurely and dumping them into telogen together.

• Illness with a high fever, or surgery. A systemic stress the body responds to by deprioritising hair.
• Childbirth. Pregnancy holds more follicles in anagen; afterwards they exit together, producing the well known postpartum shed.
• Rapid weight loss or very restrictive dieting. Hair is metabolically expensive and non essential.
• Low iron. One of the more common and most correctable causes, worth a ferritin test.
• Thyroid problems. Both underactive and overactive thyroid can alter cycling, and it is checked with a blood test.
• Severe psychological stress. Real, though the internet reaches for it too readily and the sufferer investigates it too rarely.
• Androgenetic changes. Different mechanism: rather than pushing hairs into telogen, it progressively shortens anagen and miniaturises follicles over years.

That last one is worth separating out, because it is the only entry on the list that changes the follicle itself rather than its timing. Our guide to pattern hair loss covers how that progression works.

Hair loss, shedding and breakage are three different problems

People arrive at a hair growth cycle diagram because they have noticed something changing, and the diagram only helps if you know which of these you are looking at.

• Hair shedding is a cycle problem. Too many follicles entered telogen at once. The hairs that fall are full length with a small white club at the root. The follicles are healthy and the density returns.
• Hair loss is a follicle problem. The follicle itself is miniaturising or being destroyed, as in androgenetic alopecia or alopecia areata. New hairs come through finer and shorter each cycle, or not at all.
• Hair breakage is a fibre problem, and nothing to do with the cycle. Strands snap along their length from heat, bleach or tension, leaving short broken pieces with no bulb. Your density is unchanged, but your length and thickness are not.

The white bulb test settles it quickly: full length hairs with a tiny pale bulb are shed hairs, and short pieces without one are breakage. The three mechanisms behind thinning hair goes through this in more detail.

How do you support a healthy cycle day to day?

Start with the honest limit. Nothing you buy in a bottle rewrites the schedule in a hair growth cycle diagram. Anagen length is genetic, telogen lasts about three months whatever you do, and any product promising to speed that up is overselling.

What is genuinely within your control is different, and it matters more than people expect. A hair that grows for four years and then snaps at the shoulder never gets seen at its full length. Retention, not stimulation, is where most visible improvement actually comes from.

• Eat enough, including protein and iron. Hair is one of the first things the body economises on. Persistent shedding is worth a ferritin and thyroid blood test rather than a supplement guess.
• Reduce mechanical stress. Detangle from the ends upward on conditioned hair, use a wide tooth comb, and give tight ponytails and buns a rest.
• Lower the heat. Most straighteners run far hotter than they need to. Always use a heat protectant.
• Wash regularly rather than sparingly. A clean, comfortable scalp is a better environment than a congested one, and the hairs you see in the shower were already released.
• Give it time before you judge. Any real change takes a full cycle to become visible. Assess at six months, not six days.

On products, the sensible role is everyday care that keeps grown hair intact and the scalp comfortable. Watermans products are cosmetic. They do not change the cycle, and we would rather say so than imply otherwise.

Grow Me® Hair Growth Shampoo, £14.95

Sulfate free, vegan and made in the UK, with biotin, caffeine, rosemary and niacinamide. A gentle regular cleanse that supports a healthy scalp environment and fuller looking hair.

Condition Me® Hair Growth Conditioner, £13.95

Slip is what stops strands tearing during detangling. Since anagen can run for years, protecting length you already grew is the highest value thing you can do.

Grow More® Elixir Scalp Serum, £25.50

A leave on overnight serum for areas where density has dropped, with rosemary, caffeine and niacinamide. Cosmetic scalp care, used as part of a routine rather than instead of a blood test.

Over 5 million bottles sold since 2012. Vegan and made in the UK.

Frequently asked questions

What are the stages in a hair growth cycle diagram?

Anagen (growth, two to seven years), catagen (transition, two to three weeks), telogen (rest, about three months) and exogen (release of the old hair, overlapping telogen). Older versions of the diagram show only three stages and fold exogen into telogen, which is why you will see both versions.

How fast does hair grow?

Roughly one centimetre a month on the scalp, or about six inches a year, with genuine variation between individuals and some seasonal variation. Nothing reliably speeds this up. Claims to the contrary are usually measuring reduced breakage rather than faster growth.

Why will my hair not grow past a certain length?

Either your anagen phase is genetically short, so hairs are released before they get longer, or you are losing length to breakage as fast as you gain it. The two are easy to tell apart: with short anagen you see full length hairs with a white bulb in your brush, and with breakage you see short broken pieces with no bulb.

How many hairs is it normal to shed each day?

Fifty to a hundred, and more on days you wash if you do not wash daily, because several days of released hairs come out at once. What matters is a sustained change from your own normal, not the count on any single day.

Why did my hair shed months after a stressful event?

Because telogen lasts about three months. The stress pushed a batch of follicles out of anagen, they then had to complete their resting phase, and only at the end of it did they let go. The two to three month delay is the signature of telogen effluvium, and it is why the cause is so often missed.

Can any product speed up the hair growth cycle?

No cosmetic product changes the cycle's timing. Anagen duration is set by your genetics and by how many times the relevant cells can divide. What good care changes is how much of the hair you grow survives to be seen, which is a different lever and a real one.

Do the eyebrows and eyelashes follow the same cycle?

They follow the same four phases but on a far shorter timetable, with anagen measured in weeks rather than years. That short anagen is exactly why they reach a set length and stop, and why a plucked eyebrow takes a couple of months rather than years to return.

Does cutting hair make it grow faster?

No. Growth happens at the follicle, below the skin, and scissors cannot reach it. Regular trims help because removing split ends stops splits travelling up the shaft, so you retain more of what you grow. That looks like faster growth and is really less loss.

The short version

A hair growth cycle diagram maps four stages: anagen for years of growth, catagen for a few weeks of transition, telogen for about three months of rest, and exogen for the release. Around 85 to 90 percent of your hairs are growing right now and 10 to 15 percent are resting, each follicle on its own clock, which is why 50 to 100 hairs a day in the brush is normal. Nothing in a bottle rewrites that schedule. What you can change is how much of the hair you grow survives handling, heat and tension, and that is where visible improvement actually comes from.

Sources & references

• Martel JL, Miao JH, Badri T, Fakoya AO, Physiology, Hair, StatPearls, NCBI Bookshelf. Source for the three named phases, that anagen lasts several years, that catagen lasts a few weeks, that about 10 to 15 percent of hairs are in telogen, the club hair description, and the limited number of cell divisions that sets anagen duration.
• NHS, Hair loss. NHS guidance on hair loss, when to see a GP and what happens at the appointment.
• National Institute for Health and Care Excellence, Clinical Knowledge Summary: alopecia areata. The UK primary care framework for one of the follicle level conditions described above.
• DermNet, Telogen effluvium. Dermatology reference on the delayed shed that follows a body stress.
• British Association of Dermatologists, Information leaflets on skin, hair and scalp conditions. Dermatologist reviewed leaflets, including hair and scalp topics.

Watermans products are 100% cosmetic and do not treat medical hair loss. Individual results may vary. This article is general information, not personal medical advice. If your shedding is heavy or persistent, please see your GP.