In what stage of hair growth does the club hair begin forming?

The club hair begins forming during the catagen stage of hair growth. This phase is transitional, marking the end of the anagen (growth) phase and preceding the telogen (resting) phase. During catagen, the hair follicle shrinks, and the lower part of the hair strand breaks down, which leads to the formation of the club hair. This is characterized by the hair becoming detached from the growing follicle but still remaining below the skin's surface for some time. The presence of club hairs indicates that the active growth of the hair has ceased and that it is now moving toward resting before eventually shedding. Understanding this process highlights the dynamic nature of hair growth and the hair cycle's stages.