The hair growth cycle refers to the process by which our hair grows, naturally falls out, and regrows. This cycle has a huge impact on the health and condition of your hair, so understanding it will help you treat and care for your hair. In this article, we’ll break down the four main stages of the hair cycle—anagen, catagen, telogen, and early anagen—and explain how each phase affects your hair.
- Anagen Phase
Overview: The anagen phase is the most active stage of hair growth. The cells in the hair follicle divide, causing the hair to grow longer and thicker. At this stage, hair continues to grow from the scalp.
Duration: The growing season usually lasts from 2 to 7 years. This period varies depending on individual genetics and age, and can last up to 10 years in some people.
Characteristics: At this stage, approximately 85-90% of the hair on the scalp is in the growth phase. The longer the growth phase, the longer the hair.
- Catagen Phase
Overview: Catagen is the stage where the anagen phase ends and hair growth stops. During this stage, the hair follicle shrinks and the hair root begins to separate from the scalp.
Duration: The catagen phase is relatively short, lasting about 2-3 weeks.
Characteristics: At this stage, the hair no longer grows, but is still attached to the scalp and preparing for the next stage. Approximately 1-3% of the hair on the scalp is at this stage.
- Telogen Phase
Overview: Telogen is the stage when hair completely stops growing and eventually falls out. During this stage, the hair follicle enters a resting state and is ready for new hair growth to begin.
Duration: The dormant phase lasts about 3-4 months.
Characteristics: At the end of the telogen phase, the hair falls out and new hair enters the anagen phase and begins to grow. Approximately 10-15% of the hair on the scalp is at this stage.
- Initial growth stage (Exogen Phase)
Overview: Some researchers also define a separate stage as part of the telogen phase called “early growth phase.” During this stage, new hair begins to grow while old hair falls out.
Duration: The early growth phase occurs at the end of the resting phase and can last from several weeks to several months.
Characteristics: It is considered a preparatory stage for the hair growth cycle to enter the growth phase again.
These cycles occur at different times for each individual hair, so you usually don’t lose large amounts of hair all over your scalp at once. However, when these cycles are disrupted due to stress, illness, or hormonal changes, hair loss can increase.
Summary
The hair growth cycle consists of four main stages: anagen, catagen, telogen, and early anagen. Each stage has its own period and characteristics, forming the rhythm of hair growth and shedding. The anagen phase is when your hair is at its longest, the catagen phase is when growth stops, and the telogen phase is when your hair falls out and prepares for new hair growth. The early growth stage is the stage when new hair begins to grow. These cycles occur at different times for each individual hair, and although it is rare for a large amount of hair loss to occur on the entire scalp at once, stress, illness, hormonal changes, etc. can have an effect. Understanding the hair cycle can help you maintain healthy hair and understand the causes of hair loss.
