The Hair Growth Cycle: Part 2

"Healthy Hair Begins with a Healthy Growth Cycle."

Many people think hair grows non-stop throughout life. In truth, each hair follicle goes through a natural growth cycle with different stages. Understanding this cycle helps hairdressers, trichologists, and salon professionals recognize normal hair shedding, hair thinning, and various hair loss issues.  

Knowing the hair growth cycle also allows professionals to recommend appropriate treatments, hair care routines, scalp therapies, and realistic expectations for clients.

The Hair Growth Cycle  

Each hair follicle works independently and goes through four stages:  

  • Anagen (Growth Phase)  
  • Catagen (Transition Phase)  
  • Telogen (Resting Phase)  
  • Exogen (Shedding Phase)  

Since each follicle is in a different stage, we do not lose all our hair at once.  

1. Anagen Phase – The Growth Stage  

The Anagen phase is when hair grows actively. During this phase:  

Hair cells divide quickly. The hair root gets nutrients and oxygen from blood vessels. New hair is constantly produced. Hair gets longer every day.  

Duration  

Scalp hair: 2 to 7 years 
Eyebrows: 2 to 3 months
Eyelashes: 4 to 11 months 
About 85 to 90% of scalp hair is usually in the Anagen phase.  

Growth Rate

Healthy scalp hair grows approximately:

  • 1–1.5 cm per month
  • 12–18 cm per year

The longer the Anagen phase lasts, the longer the hair can grow. Factors That Affect the Anagen Phase  : 

  • Genetics  
    Age 
    Hormones 
    Nutrition 
    Stress 
    Illness 
    Medications 
    Scalp health  

A healthy scalp encourages stronger, longer-lasting hair growth.  

2. Catagen Phase, The Transition Stage  

The Catagen phase is a short transition period. During this stage:  

  • Hair growth stops.  

  • The follicle shrinks.  

  • Blood supply to the hair root decreases.  

  • The hair separates from its nourishment.  

Only 1-2% of scalp hair is in this phase. Duration:

Approximately 2-3 weeks.  This is the shortest stage in the hair growth cycle.  

3. Telogen Phase, The Resting Stage  

The Telogen phase is the resting period. The hair stays attached inside the follicle but no longer grows. Meanwhile:  

  • The follicle prepares to produce a new hair.  

  • The old hair remains in place until it is naturally released.  

Around 10-15% of scalp hair is in the Telogen stage. Duration: 

Usually 2-4 months.  

4. Exogen Phase, The Shedding Stage  

The Exogen phase is when the old hair naturally falls out. As a new hair begins growing underneath, it pushes out the old hair gently. Normal daily hair shedding ranges from:  

50-100 hairs per day.  

This is completely normal and should not cause concern. Why Hair Falls Out : Hair shedding becomes noticeable when the natural cycle is disturbed. Common causes include:  

  • High fever  

  • Childbirth  

  • Severe stress  

  • Poor nutrition  

  • Hormonal changes  

  • Thyroid disorders  

  • Certain medications  

  • Rapid weight loss  

  • Scalp diseases  

When these issues are fixed, hair growth often returns to normal.  

Hair Growth Cycle and Salon Services  

Understanding the growth cycle helps salon professionals:  

  • Explain normal hair shedding to clients.  

  • Recommend suitable scalp treatments.  

  • Identify signs of excessive hair loss.  

  • Set realistic expectations for hair growth.  

  • Advise clients after chemical treatments or hair transplant procedures.  

Hairdressers should know when hair loss is normal and when a client should be referred to a dermatologist or trichologist.  

Interesting Facts  

Every person has about 100,000 hair follicles on the scalp. 
Each follicle can produce multiple hairs during a lifetime. 
Hair grows faster in younger individuals than in older adults. 
Hair typically grows faster during warmer months. 
Hair cannot continue growing forever because each follicle has a genetically determined growth cycle. 

Hairdresser's Professional Tip :

Do not promise rapid hair growth to clients. No shampoo, oil, serum, or treatment can dramatically increase the natural growth rate. Professional products can improve scalp health and reduce breakage, helping hair reach its maximum potential length.  

Key Takeaways :

  • Hair grows in four natural stages: Anagen, Catagen, Telogen, and Exogen.  

  • Around 85-90% of scalp hair is actively growing at any given time.  

  • Losing 50-100 hairs daily is normal.  

  • Healthy hair starts with a healthy scalp and balanced nutrition.  

  • Understanding the hair growth cycle helps professionals identify normal shedding, recognize abnormal hair loss, and recommend appropriate care.


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