Scalp RenewalThe hair growth cycle, explained
5 min read
Anagen, catagen, telogen and exogen — why shedding is normal and when it stops being normal.
Four phases, always running at once
Every follicle on your scalp runs its own independent clock. Roughly 85–90% of follicles are in anagen (active growth), which lasts two to seven years and determines how long your hair can get.
Catagen is a short two-week transition where the follicle detaches from its blood supply. Telogen is a three-month rest, and exogen is the release of the old shaft — the hairs you see in the shower.
Why 50–100 hairs a day is normal
Because roughly 10% of around 100,000 follicles are resting at any moment, a daily loss of 50–100 hairs simply reflects normal exogen turnover.
The signal that matters is not the count but the trend: a widening part, a receding density at the temples, or a sudden increase that persists past six weeks.
What a regimen can and cannot change
Topicals and constitutional support work by lengthening anagen and shortening telogen. They cannot revive a follicle that has already scarred over.
This is why early, consistent action outperforms aggressive late action, and why photo tracking every four weeks is worth the small effort.