The telogen phase is the resting stage of the hair growth cycle, lasting about two to three months on the human scalp. During this time, the hair follicle is inactive and no longer producing new hair fiber. The old hair remains anchored in the follicle as a “club hair,” sitting in place while, deeper down, a new hair slowly begins to form at the base.
Where Telogen Fits in the Hair Cycle
Your hair grows in a continuous four-phase cycle: anagen (growth), catagen (regression), telogen (rest), and exogen (shedding). Each follicle on your scalp moves through this cycle independently, which is why you don’t lose all your hair at once.
During anagen, the follicle actively builds a hair shaft. This phase lasts two to seven years on the scalp, which is why scalp hair can grow so long. In catagen, the follicle shrinks over a few weeks and detaches from its blood supply, signaling the end of active growth. Then telogen begins. The follicle essentially goes dormant, holding the old hair in place but doing no real work for roughly two to three months. At any given time, about 5 to 15 percent of your scalp hairs are in the telogen phase.
What Happens Inside the Follicle
Telogen isn’t completely silent. While the old hair sits idle, a new hair starts developing at the base of the follicle. As this new hair matures, it gradually pushes upward. Eventually it displaces the resting club hair, which loosens and falls out. That transition from resting to shedding is sometimes called the exogen phase, and it marks the end of telogen and the beginning of a fresh anagen cycle.
The shift from rest to regrowth is controlled by competing chemical signals in the skin. Certain proteins keep the follicle’s stem cells quiet during telogen by blocking cell division. When those signals weaken and a different set of growth-promoting signals ramps up, the stem cells activate and the follicle re-enters anagen. This balance between “stay quiet” and “start growing” signals is what determines how long a follicle stays in the resting phase.
What a Telogen Hair Looks Like
If you pull out or collect a hair that was in the telogen phase, you’ll notice a small, pale, rounded bulb at the root end. This is called a club hair. Unlike an actively growing hair, which has a dark, elongated root surrounded by a translucent sheath, a club hair has a dry, bulbous tip with no sheath and no pigment at the base. Finding club hairs in your brush or shower drain is completely normal. Most of the loose hairs you see day to day are telogen club hairs that were pushed out by new growth.
Normal Daily Shedding
Healthy adults typically shed fewer than 100 hairs per day. Studies of women without hair loss complaints found that most rated their daily shedding well below that threshold. Because each follicle cycles at its own pace, this daily loss is spread evenly across the scalp and is replaced by new anagen hairs at roughly the same rate, so overall hair density stays stable.
When Too Many Hairs Enter Telogen
Sometimes a stressor pushes a large number of follicles into the telogen phase all at once. The result is a condition called telogen effluvium, a wave of noticeable, diffuse hair shedding that typically hits two to three months after the triggering event. By the time you notice clumps of hair falling out, the trigger is usually already in the past.
Common triggers include:
- Physical stress: high fever, major surgery, serious illness, significant blood loss, or difficult labor
- Emotional stress: prolonged or severe psychological distress
- Hormonal shifts: postpartum hormone withdrawal is one of the most recognized causes. During pregnancy, elevated estrogen keeps more hairs in anagen longer than usual. After delivery, those overdue hairs all transition to telogen simultaneously, leading to dramatic shedding a few months later.
- Nutritional deficiency: iron deficiency and zinc deficiency are both linked to telogen effluvium
- Thyroid disorders: both overactive and underactive thyroid function can disrupt the hair cycle
- Crash dieting or severe calorie restriction
- Certain medications: some blood pressure drugs, hormonal contraceptives, and others can shift follicles into early telogen
Telogen effluvium is usually self-limiting, resolving within about six months once the trigger is removed. Because the follicles are not damaged, just prematurely resting, they re-enter anagen on their own and new hair grows back at its normal rate.
Why the Telogen Phase Matters for Hair Health
Understanding telogen helps explain several things people notice about their hair. Seasonal shedding, for example, happens because more follicles enter telogen in late summer and shed in the fall. The two-to-three-month delay between a stressful event and visible hair loss also makes sense once you know how long telogen lasts: the hair doesn’t fall out during the stress itself but months later, when the resting phase ends and new growth pushes the old club hairs free.
If you’re experiencing what feels like excessive shedding, pay attention to timing. Think back two to three months for a possible trigger. If shedding continues beyond six months without an obvious cause, or if you notice thinning in specific patches rather than diffuse loss across the scalp, that pattern points to something other than simple telogen effluvium and is worth investigating further.