Which hair growth phase is primarily responsible for actual hair lengthening during growth cycles?

• A. Anagen
• B. Catagen
• C. Telogen
• D. Exogen

Answer: (A)

Actual hair lengthening happens during the active growth phase, when the follicle is actively producing the hair shaft. In this phase, cells at the base of the follicle divide rapidly and keratinize to form the hair shaft, so length increases as the hair grows. The duration of this phase largely determines how long the hair can grow in a cycle—the longer the anagen phase, the longer the hair can become. Afterward comes a brief transitional phase where growth stops and the follicle tightens, then a resting phase with no growth, and finally shedding. So, the phase that drives real lengthening is the active growth phase known as anagen.