The hair growth cycle in transplanted hair: anagen, catagen, telogen and how surgical trauma affects each phase. Dr. Arslan Musbeh, Hairmedico Istanbul.
The three phases of the hair growth cycle
Anagen (active growth): Follicle actively produces hair. Lasts 2–7 years for scalp hair. Hair grows approximately 1cm per month.
Catagen (transition): Follicle transitions from active production to rest. Lasts 2–3 weeks. Hair shaft detaches from follicle base.
Telogen (resting): Follicle dormant. Lasts approximately 3 months. Detached hair shed when new anagen hair pushes through from below.
What surgery does to the growth cycle
Surgical trauma forces transplanted follicles into telogen. Physical and chemical stress — extraction trauma, handling, temperature change, vascular disruption — all trigger the telogen transition. The subsequent dormant period (months 1–3) is this surgery-induced telogen phase. The follicle is alive and intact; not producing hair shaft growth. When telogen ends, the follicle transitions back into anagen and produces a new, permanent shaft.
Long-term cycle in transplanted hair
After maturation (months 12–14), transplanted hair follows a normal growth cycle indistinguishable from native hair. It sheds and regrows naturally. It responds to styling, colouring and treatment like any other scalp hair. The only difference: the transplanted follicle is DHT-resistant and will not miniaturise from androgenetic alopecia.
