How many stages of hair growth are there?

The human hair growth cycle consists of three distinct stages: anagen, catagen, and telogen.

During the anagen stage, hair is actively growing, and this phase can last several years, depending on individual genetics and health. The duration of the anagen phase significantly influences hair length.

The catagen stage is the transitional phase that follows anagen, lasting only a few weeks. During this time, hair growth slows, and the hair follicle begins to shrink.

Finally, the telogen stage is the resting phase, which can last for several months. At this point, hair is no longer growing, and eventually, it will shed, allowing a new hair to begin growing from the same follicle, thus restarting the cycle.

Recognizing that there are precisely three stages helps in understanding hair behavior, treatments, and the effects of various laser therapies used in hair removal or hair restoration, as these therapies may interact with hair in different stages of its growth cycle.