The Hair Growth Cycle Explained: Anagen, Catagen, and Telogen

Every hair on your scalp moves through a repeating cycle of growth, transition, and rest. At any moment most of your follicles are actively growing while a small fraction are resting or shedding. Understanding this cycle explains why losing 50 to 100 hairs a day is normal, and why pattern baldness is really a story about the cycle breaking down.

The three phases of the hair growth cycle

The hair growth cycle has three main phases: anagen, the long growth phase; catagen, a brief transition; and telogen, the resting phase that ends in shedding. Each follicle runs through this cycle independently of its neighbors, which is why healthy hair does not all fall out at once. A fourth term, exogen, is sometimes used for the actual shedding of the old hair at the end of telogen.

About 85 to 90 percent of scalp follicles are in anagen at any time, which is why the scalp stays full despite constant turnover. The phases differ enormously in length, and that imbalance is the key to how the whole system holds together.

Hair growth cycle at a glance

Phase	What happens	Typical duration	Share of follicles
Anagen (growth)	Follicle actively produces hair	2 to 6 years	About 85 to 90 percent
Catagen (transition)	Growth stops, follicle detaches from blood supply	About 10 days	Under 1 percent
Telogen (resting)	Old hair rests, new hair forms beneath	2 to 3 months	About 10 percent

These are typical ranges from published dermatology data and vary by person and by body site.

Anagen: the growth phase

Anagen is the active growth phase, when cells in the follicle divide rapidly and push the hair longer for two to six years. The length of your anagen phase is largely genetic and sets how long your hair can grow before it is shed. Longer anagen means longer potential hair.

This phase matters most for hair loss because anything that shortens it shrinks the hair you can grow. Scalp hair spends years in anagen, while body hair has a much shorter growth phase, which is why eyebrow and arm hair never reach the length of scalp hair. Keeping follicles in anagen longer is the goal of several treatments, including minoxidil.

Catagen and telogen: transition and rest

Catagen is a short transition phase of about ten days when the follicle stops growing and detaches from its blood supply, forming a club hair. Fewer than one percent of follicles are in catagen at any time, so you rarely notice it. It is essentially the follicle winding down before a rest.

Telogen is the resting phase, lasting two to three months, during which the old club hair sits in place while a new hair begins forming beneath it. About ten percent of scalp follicles are in telogen at once. When the new anagen hair pushes up, the old one sheds, which is the 50 to 100 hairs most people lose daily. A temporary spike in telogen shedding after illness, stress, or childbirth is called telogen effluvium, which we compare with pattern loss in our guide on telogen effluvium versus baldness.

How DHT and pattern baldness disrupt the cycle

Male and female pattern baldness disrupt the cycle by progressively shortening anagen, so each cycle produces a finer, shorter hair until the follicle barely grows visible hair at all. This shrinking is called miniaturization, and the hormone driving it in genetically sensitive follicles is dihydrotestosterone, or DHT.

With each cycle the growth phase gets shorter and the resting phase makes up a larger share, so more follicles are shedding and fewer are growing long hairs. The result is the gradual thinning charted by the Norwood scale in men. Because the process targets the cycle, treatments target it too: finasteride lowers DHT to slow miniaturization, a mechanism we cover in our article on whether finasteride really stops hair loss, while minoxidil works partly by extending anagen. The role of DHT and other drivers is detailed in our guide to hair loss causes in men, and the American Academy of Dermatology lists the broader medical causes worth ruling out.

Why the cycle matters for hair transplants

The hair growth cycle is the reason transplanted hair sheds before it grows and the reason results take a year or more. Transplanted follicles are stressed by the move and many enter a resting phase, so the visible hair falls out within a few weeks. The follicle itself survives and re enters anagen on its own schedule.

That is why new growth typically starts around three to four months after surgery and keeps improving through twelve to eighteen months as more follicles cycle back into growth together. It also explains why donor hair keeps growing after transplant: follicles from the back and sides are genetically programmed for long anagen and are not sensitive to DHT, so they hold their cycle even in a balding zone. Our hair transplant results timeline tool shows how that growth unfolds month by month.

Frequently asked questions

How many hairs is it normal to lose per day? Losing 50 to 100 hairs a day is normal and reflects follicles completing the telogen phase and shedding old hairs. Consistently losing noticeably more, or seeing thinning and a widening part, can signal a cycle disruption worth evaluating.

Can you make your hair grow faster by changing the cycle? Not meaningfully. Growth rate and anagen length are mostly genetic, averaging about half an inch per month. Treatments like minoxidil can extend the growth phase in thinning follicles, but no product reliably speeds healthy hair beyond its natural rate.

Why does transplanted hair fall out before it grows? The stress of transplanting pushes follicles into a resting phase, so the visible hair sheds within a few weeks while the follicle stays alive. It re enters the growth phase on its own, with new hair usually appearing around three to four months later.

Wondering where you are in the process? Mapping your stage is the first step toward a plan. Check your stage with our Norwood scale quiz, review hair loss medications that act on the cycle, or request a free consultation with a DFW specialist.