Clients ask about hair growth and shedding more than almost any other topic in the chair, usually with some anxiety attached. Having a working knowledge of the hair growth cycle helps you answer those questions accurately, set realistic expectations, and know when a question belongs with a dermatologist instead of a stylist. This is a quick, practical refresher on the biology, written for working stylists and barbers rather than as a consumer explainer.
The Three Phases of the Hair Growth Cycle
Every hair follicle on the scalp cycles independently through three main phases: anagen (growth), catagen (transition), and telogen (resting, ending in shedding). Because follicles are not synchronized with one another, only a fraction of the hairs on any given head are shedding at once, which is why normal daily hair loss is a slow trickle rather than a single dramatic event.
Anagen: The Growth Phase
Anagen is the active growth phase, when the follicle is producing new keratinized cells and the hair shaft is lengthening. This phase typically lasts anywhere from about two to six years, and the genetically determined length of a person's anagen phase is the main reason some clients can grow hair well past their waist while others seem to plateau at shoulder length no matter how well the hair is cared for. Scalp hair grows at a fairly consistent average rate of roughly 1 to 1.5 centimeters per month across most people, though this varies with age, genetics, and overall health. Most of the hair on a healthy scalp, on the order of 85 to 90 percent, is in anagen at any given time.
Catagen: The Transition Phase
Catagen is a short transitional stage in which the follicle shrinks and detaches from its blood supply, signaling the end of active growth. It generally lasts about two to three weeks, and only a small percentage of hairs, roughly 1 to 3 percent, are in this phase at any moment.
Telogen: The Resting and Shedding Phase
Telogen is a resting phase in which the follicle is dormant and the fully formed "club hair" sits in place, no longer growing. It lasts roughly two to three months. About 10 to 15 percent of scalp hairs are in telogen at any given time, and the phase ends when the club hair is released, often as a new anagen hair begins pushing up beneath it. Some hair biology models describe this release as a distinct fifth stage called exogen, but for practical purposes it's easiest to think of it as the tail end of telogen.
| Phase | What's happening | Typical duration | Share of scalp hairs |
|---|---|---|---|
| Anagen (growth) | Follicle actively produces new hair; shaft lengthens | Roughly 2–6 years | ~85–90% |
| Catagen (transition) | Follicle shrinks, detaches from blood supply; growth stops | About 2–3 weeks | ~1–3% |
| Telogen (resting/shedding) | Follicle rests; old club hair is eventually released | Roughly 2–3 months | ~10–15% |
These are typical ranges seen across the population, not fixed numbers for every client. Hormones (including androgens), genetics, age, and overall health all influence how long each phase lasts for a given person, and growth cycles differ by body location as well; eyebrow and eyelash hairs, for example, have much shorter anagen phases than scalp hair, which is why they don't grow nearly as long.
Why This Matters in the Chair
Explaining Normal Shedding to Worried Clients
Losing somewhere in the neighborhood of 50 to 100 scalp hairs a day is considered a normal part of the telogen cycle finishing out, not a sign that something is wrong. What alarms clients is usually a noticeable increase in shedding, and a useful thing to know is that major stressors, such as illness, high fever, crash dieting, surgery, or childbirth, can push an unusually large number of follicles into telogen at the same time. Because telogen lasts a couple of months, the resulting shedding often shows up eight to twelve weeks after the triggering event, not immediately, which can be confusing for clients trying to connect the dots themselves. Being able to explain that delay, and being clear that this is a general pattern rather than a diagnosis, can go a long way in a consultation. Ongoing or severe shedding is a medical question and should be referred out to a physician or dermatologist rather than addressed with in-salon treatments.
Cut, Color, and Regrowth Planning
Because average growth rate is fairly stable for a given client, it's a useful planning number. At roughly 1 to 1.5 cm per month, you can give clients a reasonable estimate of how long it will take to grow out a cut to a target length, or how quickly a color line will need touching up as new, unpigmented anagen growth comes in at the root. It's also worth remembering that anagen duration, not just growth rate, sets a practical ceiling on maximum hair length for a given client; someone whose hair naturally sheds out of anagen sooner will hit a length plateau regardless of product use or trimming schedule, and knowing that helps you set expectations up front rather than mid-way through a long-hair goal.
Managing Expectations Around Growth Claims
Anagen duration and growth rate are driven mainly by genetics and hormones, and no cutting technique, styling product, or in-salon service changes that underlying biology. What good haircare and cutting practices actually do is protect the hair that's already growing, by reducing split ends, breakage, and mechanical damage so hair reaches greater visible length before it needs to be trimmed off. That's a meaningful and honest benefit, but it's a different claim than "grows hair faster," and it's worth keeping that distinction clear when talking with clients or evaluating any product's marketing claims.
Practical Takeaways
- Normal daily shedding is a byproduct of an unsynchronized cycle across thousands of individual follicles, not a single event.
- A spike in shedding often traces back to a stressor from roughly two to three months earlier.
- Growth rate (about 1–1.5 cm/month on average) is a practical number for estimating regrowth and touch-up timing.
- Anagen length varies by person and sets a natural ceiling on achievable hair length.
- Persistent or severe shedding and thinning should be referred to a physician, not diagnosed or treated in the chair.
- Sharp, well-maintained cutting shears reduce split ends and mechanical damage, helping hair retain length as it moves through its natural cycle.