In hair removal science, "anagen" refers to which concept?

• A. The growth phase of hair
• B. The resting phase
• C. The shedding phase
• D. The inactive phase

Answer: (A)

Anagen is the active growth phase of the hair cycle. During this stage, cells in the hair follicle’s matrix divide and keratinize to form and lengthen the hair shaft, so the hair is actively growing. The duration of this phase varies by body area and person, often lasting years for scalp hair, which is why it can grow long, while it’s much shorter for other areas. After anagen comes catagen (a short transitional phase) and then telogen (the resting phase). The shedding you hear about relates to a later part of the cycle (exogen), not the growth phase itself. Inactive isn’t a standard term for this cycle, so it doesn’t describe what anagen is.