What is the growth phase of hair called?

The growth phase of hair is known as the anagen phase. During this phase, hair follicles actively produce hair, leading to significant lengthening of the hair strand. The anagen phase can last for several years—ranging from two to seven years, depending on individual genetics and other factors. This is the most crucial phase for hair growth, as it is during this time that the hair is thickest and strongest.

In contrast, the catagen phase is a transitional stage where hair growth slows down and follicles shrink. Meanwhile, the telogen phase is the resting stage, where hair is at rest and preparation for shedding occurs. The term "increase phase" is not a widely recognized term in hair growth terminology, thus making it an unsuitable descriptor for any of the established phases of hair growth. Understanding the anagen phase is essential for practices related to hair removal and hair restoration, as it represents the time frame in which hair is most actively growing.