Anagen Phase – Active Growth: The anagen phase marks the period of active hair growth, where cells divide quickly, leading to longer hair. This growth phase is predominant, with about 90% of hair follicles in this stage at any given time, and it can last from 2 to 8 years.

Catagen Phase – Regression: The catagen phase is a transitional stage that lasts about 2 to 3 weeks. During this time, hair growth slows as cell production decreases and the hair follicle shrinks. The hair shaft begins to separate from the follicle, creating what is referred to as a "club hair."

Telogen Phase – Resting: Originating from the Greek "telo" for end and "gen" for produce, the telogen phase is the resting period of the hair cycle. It represents the end of active growth, with the follicle lying dormant for up to 3 months. Despite the pause in growth, the club hair remains in place.

Exogen Phase – Shedding: Finally, the exogen phase occurs alongside the telogen phase and involves the shedding of hair. It's a natural part of the cycle, leading to the loss of older hairs as new growth begins beneath them. This phase signals the transition back to the anagen phase, restarting the growth cycle.