Each hair grows for years (anagen), pauses for a few weeks (catagen), rests for a few months (telogen) and is then shed (exogen) as a new hair starts below it. Losing a number of hairs a day is normal; what matters is whether the regrowing hairs come back as thick as before.
Four phases
Anagen is the long growing phase; catagen is a short transition; telogen is rest; exogen is release of the old hair.
Why thinning happens
When the growing phase shortens or follicles shrink, hairs become finer and shorter, and the scalp shows more.
What this means for care
Any routine takes months to show, because you are waiting for new growing cycles. Track with photos every 4 to 8 weeks.
Questions
How many hairs a day is normal?
Everyone differs; a sudden big change is the thing to notice and check.
Why do results take months?
New hairs need time to grow long enough to see.
Studies mentioned
These studies looked at ingredients or general approaches. None of them tested our treatments or products, so they are background, not proof.
- Paus R, Cotsarelis G. The biology of hair follicles. N Engl J Med 1999;341(7):491-7.Review. Background on how hair follicles grow, rest and shed in cycles.PubMed 10441606doi:10.1056/NEJM199908123410706