What is the name of the regressive phase in the hair growth cycle?

The regressive phase in the hair growth cycle is referred to as catagen. During this phase, which typically lasts for several weeks, hair follicles undergo a process of transformation. Specifically, the hair stops growing, and the hair bulb shrinks. This regression signifies a transition from the active growth phase (anagen) to a resting phase.

During catagen, the hair detaches from its blood supply and begins to prepare for eventual shedding. This phase is critical in the hair growth cycle, as it allows for the replacement of old hairs with new ones, ensuring the health and vitality of the hair follicle over time. Understanding this phase is essential for comprehending how hair growth and shedding work, which is important in various aesthetic and medical applications in the field of laser and hair removal treatments.