During which stage does the hair shaft detach from the bulb?

The correct answer is Catagen. This stage is known as the transitional phase of hair growth, during which the hair follicle undergoes significant changes. Specifically, in the catagen phase, which follows the active growth phase (anagen), the hair shaft begins to detach from the bulb. This detachment occurs as the hair transitions from actively growing to a resting state, preparing for eventual shedding.

During catagen, the hair follicle shrinks, which causes the hair shaft to be pulled upward and away from the hair bulb. The duration of the catagen phase is relatively short, lasting only a few weeks, after which the hair enters the telogen phase, where it remains in a resting state until it is eventually shed. Understanding these stages is crucial for hair removal practices, as it helps in determining the appropriate timing for treatments aimed at effectively removing hair.