Skip to content
Quick Answer
The anagen phase is when your hair follicles actively produce new hair. It is the main growth stage of the hair cycle and determines how long each strand continues to grow.
Your hair does not grow continuously at the same rate throughout its life. Each follicle moves through different stages, and the amount of time it spends in the growth stage affects how long that individual strand can become.
The anagen phase can last for several years in scalp hair. Its duration varies from person to person and can also differ between follicles on the same scalp.
What Happens During the Anagen Phase?
During the anagen phase, cells in the hair follicle divide rapidly to produce the growing hair shaft. This activity takes place at the base of the follicle.
The newly formed cells become part of the hair shaft as they move upward and harden through keratinisation. The follicle also receives oxygen and nutrients through the blood supply around the dermal papilla.
Scalp hair grows by roughly 1 cm per month, although the rate varies between individuals. The follicle remains active throughout this growth period until it enters the next stage of its cycle. 85% to 90% of scalp hair is actively in the anagen phase at any given point.
How Long Does the Anagen Phase Last?
The anagen phase of scalp hair usually lasts around two to seven years. This wide range is one reason people naturally have different hair growth patterns and maximum hair lengths.
The hair growth phase duration depends partly on the individual follicle and genetic factors. Not every follicle on your scalp necessarily enters or leaves each stage at exactly the same time.
The length of anagen also differs across the body. Eyebrows and eyelashes have much shorter growth periods, which limits how long those hairs can become.
Generally, shortened anagen phases stem from underlying root causes (such as DHT sensitivity, gut health issues, or stress).
What Determines How Long Your Hair Can Grow?
Your maximum hair length depends largely on how quickly your hair grows and how long each follicle stays in the anagen phase.
Think of the anagen phase as the amount of time a hair follicle has to produce a strand. A follicle that remains active for two years has less time to produce a long strand than one that stays active for six years.
For example, at an average growth rate of about 1 cm per month:
-
A 2-year growth period could produce around 24 cm of growth.
-
A 6-year growth period could produce around 72 cm of growth.
These are simple estimates. Actual hair length also depends on factors such as growth rate, breakage, and the condition of the hair shaft. Cutting or trimming your hair does not extend anagen because it only removes part of the strand above the scalp. It does not change the activity of the follicle.
What Happens After the Anagen Phase Ends?
Once active growth ends, the follicle moves through catagen, telogen, and eventually exogen before beginning another cycle. These stages allow the follicle to transition from active production to rest and release of the old strand.
The hair growth cycle transitions through distinct biological phases from active production to hair shedding:
|
Stage |
What happens |
Typical duration |
|
Anagen |
The follicle actively produces the hair shaft. |
About 2–7 years |
|
Catagen |
Growth stops and the follicle enters a short transition. |
About 2–3 weeks |
|
Telogen |
The follicle rests while the old hair remains attached. |
About 2–4 months |
|
Exogen |
The old hair is released and sheds. |
Variable |
Note - These stages do not occur across your entire scalp at once. Different follicles are at different points in the cycle, which allows some hairs to keep growing while others are resting or shedding.
What Can Affect the Anagen Phase?
Several biological and health-related factors can affect normal follicle activity and the hair cycle. A change in hair growth does not automatically mean that the anagen phase has become shorter. The underlying cause needs to be considered.
The effect depends on the underlying cause and the individual:
-
Genetics: Genetic factors influence how long individual follicles remain in their growth stage.
-
Hormonal influences: Androgens can affect susceptible follicles and contribute to changes in their growth behaviour.
-
Nutritional deficiencies: Inadequate iron, protein, or other essential nutrients can interfere with normal hair production.
-
Major physical or emotional stress: Significant stressors can disrupt the normal hair cycle and trigger increased shedding.
-
Scalp conditions: Persistent inflammation or conditions such as seborrhoeic dermatitis can affect the scalp environment around the follicles.
-
Age: Hair-cycle behaviour can change as you get older, affecting growth and density.
Can You Prolong the Anagen Phase Naturally?
There is no simple home method that can reliably add years to the anagen phase. You can, however, protect normal hair growth by addressing factors that may interfere with the hair cycle.
Supporting optimal follicle activity requires addressing internal and external factors that regulate the hair growth cycle:
-
Meet your nutritional needs: Adequate protein, iron, and other essential nutrients provide the building blocks needed for normal hair production.
-
Address deficiencies: If testing identifies a nutritional deficiency, correcting it can remove one factor that may be affecting hair health.
-
Manage scalp conditions: Persistent dandruff, inflammation, or irritation should be treated rather than managed only through cosmetic hair care.
-
Address underlying health conditions: Hormonal, thyroid, or other medical conditions may require appropriate treatment.
-
Consider clinically established treatments: Some hair disorders respond to treatments that influence follicle activity. These should be selected according to the underlying condition and used with appropriate medical guidance.
What Does a Shortened Growth Phase Mean for Hair Health?
A shorter active growth period can limit how long individual strands grow and may contribute to changes in hair density when follicle behaviour is also affected.
The effect depends on the condition involved. In some hair disorders, follicles gradually produce finer strands and spend less time in active growth. In other situations, a disruption to the hair cycle can cause increased shedding without permanently changing the follicle.
This is why the pattern of hair change matters. Gradual thinning, sudden shedding, and shorter-looking strands can have different causes and may need different approaches.
Support Your Hair Growth Cycle
The anagen phase gives each hair follicle its active growth window, and its duration naturally varies between individuals. Nutrition, health conditions, hormones, genetics, and scalp health can all influence how the hair cycle behaves.
Instead of trying to force a longer growth phase, focus on keeping the factors that influence normal follicle function in good condition. If you are experiencing persistent thinning or shedding, finding the underlying cause is more useful than focusing on the hair cycle alone.
Unsure of which stage your hair is in right now and how to care for it?
Take Traya’s Hair Test for a personalised, doctor-backed hair care plan.
Frequently Asked Questions
-
How to transition hair into the anagen phase?
You cannot force hair follicles into the anagen phase overnight. However, you can support normal growth by addressing factors that may affect the hair cycle, such as nutritional deficiencies, hormonal changes, and scalp inflammation.
-
Which hair has the longest anagen phase?
Your scalp hair exhibits the longest anagen phase across the human body. The growth phase can approximately last for up to 7 years in the scalp.
-
Does cutting or trimming hair make the anagen phase longer?
No, trimming the hair does not impact the anagen phase of the hair. Trimming is only useful for removing split ends from your hair.
References :
- Hoover, E., Alhajj, M., & Flores, J. L. (2023). Physiology, Hair. StatPearls Publishing. NCBI Bookshelf ID: NBK499948. https://www.ncbi.nlm.nih.gov/books/NBK499948/
- Qi, J., & Garza, L. A. (2014). An overview of alopecias. Cold Spring Harbor Perspectives in Medicine, 4(3), a013615. https://doi.org/10.1101/cshperspect.a013615 Cited by: 145
- Natarelli, N., Gahoonia, N., & Sivamani, R. K. (2023). Integrative and mechanistic approach to the hair growth cycle and hair loss. Journal of Clinical Medicine, 12(3), 893. https://doi.org/10.3390/jcm12030893
- U.S. National Library of Medicine. (2022). Hair Loss (Alopecia). MedlinePlus Medical Encyclopedia. https://medlineplus.gov/hairloss.html
Read More Blogs
Olive Oil for Dandruff Control: Benefits, Risks & How to Use
White flakes on a black shirt can feel embarrassing, and the constant itching makes it ...
Is Showering Safe After a Derma Roller Session?
Quick Answer Showering immediately after a derma roller session is not safe. At-hom...
Is Cold Water Better Than Hot Water for Shampooing?
Quick Answer No. Cold water is not necessarily better than hot water for washing yo...
Double Conditioning: Is It Useful?
Hair that feels rough even after washing can make you wonder if one round of conditione...
Castor Oil Patch Test: How to Check for Allergy
That thick, glossy layer of Castor Oil might promise softer hair or calmer skin, but if...
