The growth and loss of hair on your head might seem like a simple process – after all, we lose up to 50-100 strands of hair a day1. But there’s a lot more science to it. Your hair has a unique growth cycle consisting of four distinct stages – each with a timeline that can be influenced by different factors such as your age, diet, and overall health2.
Read on to discover more about the distinct stages of the hair growth cycle, and what you can do to promote a healthy growth cycle for your hair today.
In this guide:
What is the hair growth cycle?
Stages of the hair growth cycle
Healthy lifestyle habits to consider
Hair growth cycle FAQs
1. https://www.healthline.com/health/how-much-hair-loss-is-normal
What is the hair growth cycle?
Like skin, hair is formed by the rapid growth and division of specialised cells. These cells are known as keratinocytes3, and they move upwards from beneath your skin at the rate of about six inches a year to form keratin4. At any point in time, all the hair on your body was formed by a string of dead keratinised cells3.
The hair growth cycle occurs in four distinct stages: anagen, catagen, telogen and exogen. The first three stages cover the growth, maturity, and changes the hair follicles undergo to produce each hair strand. While the exogen phase, the final phase, looks at how old hairs make way for new ones2.
On average, your scalp is covered with about 100,000 to 150,000 hairs. Scalp hair usually grows most of the time, but you’ll also lose up to 100 hairs a day as you go about your day-to-day activities4.
You can also experience hair thinning [LM1] or hair loss when some of your hair follicles are programmed or stimulated to have a shorter hair growth cycle due to factors such as age, genetics, hormones, stress and illness4.
See our video below for a better idea of the hair growth cycle.
3. https://www.ncbi.nlm.nih.gov/books/NBK499948/
4. https://www.webmd.com/skin-problems-and-treatments/hair-loss/understanding-hair-loss-basics
3. https://www.ncbi.nlm.nih.gov/books/NBK499948/
2. https://www.healthline.com/health/stages-of-hair-growth
4. https://www.webmd.com/skin-problems-and-treatments/hair-loss/understanding-hair-loss-basics
4. https://www.webmd.com/skin-problems-and-treatments/hair-loss/understanding-hair-loss-basics
Stages of the hair growth cycle
Let’s now look at each phase in more detail to understand the role they play in the hair growth cycle.
Anagen phase
Anagen has the longest timeline of all stages, and it can be for about two to eight years for the hairs on your head. The length of the anagen stage will also differ depending on the type of hair. Typically, scalp hair remains in this phase for a shorter time compared to pubic hair or eyebrows.
During this stage, hair follicles produce hairs that continuously grow until they’re cut, or naturally shed at the end of their cycle. About 90% of all the hairs on your head are always in the anagen phase2.
Catagen phase
The catagen phase begins once the anagen phase comes to an end. During this stage, hair follicles shrink, growth slows, and the hair detaches from the base of the hair follicle but remains in place for its final days of development. This stage has a timeline of roughly two weeks, and only one to three percent of the hair on your scalp is always in the catagen phase2.
Telogen phase.
The telogen, or resting, phase usually affects nine percent of your scalp hairs at any given time. During this stage, your hair growth pauses, but hair doesn’t fall out as well. At the same time, new hairs begin developing in follicles that have recently shed hair from the catagen phase. The telogen phase typically lasts around three months2.
Exogen phase
The exogen, or shedding, phase is when hair sheds from the scalp – and it can be accelerated by brushing or washing your hair. It’s completely normal to lose up to 50 to 100 strands of hair per day during the exogen phase. This phase can last for several months as new hairs take the place of old ones that have been shed2.
2. https://www.healthline.com/health/stages-of-hair-growth
2. https://www.healthline.com/health/stages-of-hair-growth
2. https://www.healthline.com/health/stages-of-hair-growth
2. https://www.healthline.com/health/stages-of-hair-growth
Hair growth cycle timeline
A diagram showing how the hair follicle appears at each of the different phases of the hair growth cycle.
Healthy lifestyle habits to consider
There are some healthy lifestyle habits you can adopt today to maintain your hair growth cycle. These include:
Proper hair care
The following may make a difference:
Avoiding using steaming hot water when shampooing
Using a clean towel to gently dry your hair, as its most vulnerable when wet
Using a low heat setting when drying your hair2.
Reducing stress
Physical and mental stress can contribute to certain hair conditions that affect your hair cycle, leading to premature hair loss. These include:
Telogen effluvium. A condition that increases hair transition from the anagen to telogen and exogen phases, potentially increasing daily hair loss threefold.
Trichotillomania. A psychological condition where a person develops an irresistible urge to pull out hair from their head and other regions of the body.
Alopecia areata. An immunological condition where your immune system attacks healthy hair follicles, resulting in hair loss.
This is why it’s important to include stress-relief techniques in your life. The likes of yoga, meditation, counselling and avoiding daily stress triggers could translate to positive health benefits2.
Good nutrition
Good nutrition is important for healthy hair. Remember, hair is largely made up of proteins, so filling your plate with a healthy serving of protein-rich options can be beneficial. These include:
Low-fat dairy products
Legumes
Beans
Fish
Lean meats2.
Nutrients also contribute to healthy hair growth. Don’t forget to get a sufficient intake of nutrients such as:
Iron (especially if you’re a woman)
Vitamin C
Vitamin D.
Other essential nutrients that may be associated with normal healthy hair include vitamin B12, folic acid, and zinc2.
2. https://www.healthline.com/health/stages-of-hair-growth
2. https://www.healthline.com/health/stages-of-hair-growth
Hair growth cycle FAQs
How long is the hair growth cycle?
The longest phase of your hair growth cycle is the anagen phase, which can last anywhere from two to eight years. If we factor in that the second longest phase, exogen, can last several months, then your hair cycle can take anywhere from two and a half years to eight and a half years2.
How long does a hair-shedding cycle last?
The hair-shedding cycle, also known as the exogen phase, can take several months as new hairs take the position of previous ones that have been shed2.
Does hair grow in seven-year cycles?
That may vary from person to person. Some people can have a shorter hair growth cycle of only two years, while others may have a longer hair growth cycle of up to eight and a half years2.
Does hair stop growing at a certain length?
No, hair does not stop growing at a certain length. It can only stop growing once it reaches the end of its life span, or growth cycle, or if you cut it and it falls off2.
2. https://www.healthline.com/health/stages-of-hair-growth
2. https://www.healthline.com/health/stages-of-hair-growth