The hair life cycle, also known as the hair cycle, is divided into three main phases: anagen, catagen and telogen. These phases occur continuously and sequentially on every hair follicle in the human body. Here is an overview of each phase:

The life cycle of hair is on average between 2 and 7 years. Each follicle produces a new hair, which grows in a succession of cycles until it falls out.

Anagen

It is the active growth phase of hair. In this phase, the cells of the hair follicle multiply rapidly and the hair grows in length. The duration of anagen can vary from a few months to several years, depending on the area of the body and the type of hair. For example, scalp hair has a longer anagen than body hair.

Catagen

This is a short and temporary transition phase that marks the end of active hair growth. During catagen, the hair follicle contracts and the production of melanin, which is the pigment responsible for hair color, stops. This phase only lasts about 2-3 weeks.

Telogen

It is the resting phase in which the hair no longer grows and the hair follicle is inactive. During this phase, the hair is still anchored to the follicle, but is ready to be expelled. The length of the telogen phase varies, but typically lasts about 3-4 months.

After the telogen phase, the hair falls out naturally (a phenomenon known as hair multiplication) and the cycle begins again with a new anagen phase, during which a new hair begins to grow in the follicle. This cycle continues throughout life, with hair constantly growing, falling out and being replaced. However, some factors such as age, stress, illness and hormonal changes can affect the hair cycle, causing variations in the length of the phases and abnormal hair loss.

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• Knowing your hair | Hair life cycle
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