How does hair cycle affect timing of laser sessions?

How does hair cycle affect timing of laser sessions?

• A. Only hairs in the anagen (growth) phase respond best; multiple sessions over weeks or months are needed.
• B. All hairs respond equally in a single session.
• C. Timing doesn't matter; any day is fine.
• D. Sessions should be daily.

Answer: (A)

Hair grows in cycles, with a growth phase (anagen), a transitional phase (catagen), and a resting phase (telogen). Laser treatment works best on hairs in the anagen phase because they contain the pigment and are actively connected to the follicle, so the energy from the laser can heat the follicle and suppress regrowth. But at any moment, most hairs are in different phases, so a single session won’t affect every hair. Scheduling multiple sessions over weeks gives hairs time to cycle back into anagen, where they can be treated effectively in subsequent passes. The exact timing depends on the area and the person’s cycle length, but sessions are typically spaced several weeks apart (not daily).

Hair grows in cycles, with a growth phase (anagen), a transitional phase (catagen), and a resting phase (telogen). Laser treatment works best on hairs in the anagen phase because they contain the pigment and are actively connected to the follicle, so the energy from the laser can heat the follicle and suppress regrowth. But at any moment, most hairs are in different phases, so a single session won’t affect every hair. Scheduling multiple sessions over weeks gives hairs time to cycle back into anagen, where they can be treated effectively in subsequent passes. The exact timing depends on the area and the person’s cycle length, but sessions are typically spaced several weeks apart (not daily).