Encyclopedia
Science
The Hair Growth Cycle
The three phases every hair goes through — anagen, catagen, telogen — and why they explain beard genetics.
Every hair on the human body follows a three-phase cycle: anagen (growth), catagen (transition), telogen (rest). Beard hairs have shorter anagen phases than scalp hairs — which is why beards top out at 24–36 inches while scalp hair can grow to 30+. The length of your anagen phase is genetic and non-modifiable.
Key Facts
- ›Anagen: growth phase, 2–6 years for scalp, 2–3 years for beard.
- ›Catagen: transition, 2–3 weeks.
- ›Telogen: rest, 2–3 months, then hair sheds.
- ›Anagen length is genetic — can't be extended.
- ›Beard maxes out at 24–36 inches for most men.
Why 'growth serums' can't override genetics
No product can extend the anagen phase past its genetic ceiling. Products like castor oil and Grizzly Gold Standard Beard Oil support follicle health — meaning existing hairs grow to their full genetic length in optimal condition. That's a real, visible improvement, but it's not 'unlocking' longer growth.
