The Hair Life Cycle: Three Phases
Every strand moves through a cycle: it grows, it rests, it sheds — then begins again.
Phase 1 — Anagen (the growth phase)
In the anagen phase, the follicle is actively producing hair. This phase lasts between 2 and 7 years for most people. It is the length of this phase — largely set by genetics — that decides how long your hair can get. Someone with a long anagen phase can grow hair to the waist; another with a short phase may never pass the shoulders, even with the same care. At any moment, about 85 to 90 percent of your hair is in this phase.
Phase 2 — Catagen (the transition phase)
After growth, the strand enters a short transition phase called catagen, lasting about 2 to 3 weeks. During this time the follicle stops producing and begins to shrink. The strand detaches from its blood supply but stays in place. Only a small percentage of your hair is in this phase at any given time.
Phase 3 — Telogen (the resting and shedding phase)
In the telogen phase, the strand rests for about 3 months. At the end of this phase it sheds — and a new strand begins growing in the same follicle, restarting the cycle. This is why losing 50 to 100 hairs a day is completely normal. It is not hair loss; it is renewal. The problem arises only when many follicles enter the shedding phase at once (we cover that in the next lesson).
Key takeaways
- Hair moves through three phases: anagen (growth), catagen (transition), telogen (rest/shed).
- The length of the anagen phase (2-7 years) decides how long your hair can grow.
- Losing 50 to 100 hairs a day is normal — it is renewal, not loss.