What are the three phases of hair growth?

The three phases of hair growth are indeed Anagen, Catagen, and Telogen. Each phase plays a crucial role in the hair growth cycle.

1. Anagen phase is the active growth stage where the hair follicles produce new hair cells continuously. This phase can last several years, which determines the length of the hair.

2. Catagen phase is a transitional stage that lasts for a few weeks. During this phase, hair growth slows down, and the hair follicles shrink. This is an important phase as it prepares the hair for eventual shedding.

3. Telogen phase marks the resting stage where the hair is not actively growing. The hairs can remain in this phase for several months before they are shed and new hair begins to grow, which then returns to the Anagen phase.

The other options do not accurately represent the well-known hair growth cycle. "Metagen" is not recognized in hair growth terminology, while "Exogen" refers to the shedding of hair but is not one of the main phases. "Progen" is also not a standard term in the context of hair growth. Thus, identifying Anagen, Catagen, and Telogen as the three phases highlights the correct understanding of the hair growth cycle.