During electrolysis, the probe should be inserted to the depth corresponding to the average depth of which hair growth phase?

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

Answer: (B)

During electrolysis you want to reach the deepest part of the follicle where the active growth occurs. That deepest, most active portion sits during the anagen phase, when the hair is actively growing and the hair bulb is at its lowest, deepest position in the dermis. Targeting this depth ensures the energy reaches the hair matrix and bulb to disrupt the follicle and prevent regrowth. In other phases, like catagen (transitional) and telogen (resting), the follicle is shorter or dormant, so placing the probe at their average depths would miss the active structure you need to affect. Exogen is simply shedding; not the phase that requires treatment. So the correct choice is the growth phase where the follicle is deepest and most active.