The hair on your head grows from a root known as a follicle, which extends out from underneath the skin on your scalp. Each strand of hair has its own life cycle. Growth happens in four stages: anagen, catagen, telogen, and exogen. The hair cycle includes phases where hair is actively growing and phases of rest where no active growth is happening.
Factors like genetics, age, medical conditions, hair care habits, and stress can all affect hair growth. Here's what to know about each stage.
The first stage of hair growth is the anagen phase, a period of active growth. During this time, the cells in the hair follicles work rapidly to continuously grow new hair strands.
Anagen is the longest phase of the hair growth cycle, lasting anywhere from 2-8 years for hair on the scalp. This phase gets shorter with age, so hair doesn't tend to grow as much as a person gets older.
During a normal hair cycle, most strands on your head will be in the anagen stage at any given time.
The 8 Best Vitamins for Healthy Hair Growth, According to Experts
Stage 2: Catagen Phase
The catagen phase is the second stage of hair growth. This is a transition phase when hair shifts from active growth to a non-growth period.
This phase is substantially shorter than the anagen phase—about two weeks. Hair growth slows throughout the catagen phase. The hair follicle shrinks, and the hair strand gets ready to detach from the follicle (though it still remains).
At any point, a very small percentage of the hair follicles on your head are in this stage.
Telogen is the third stage of hair growth. This is the resting stage, where your strands remain mostly dormant.
During this phase, old hair is preparing to shed, and new hair is preparing to grow in its place. Telogen usually lasts 5-6 weeks for hair on the scalp.
While 10% or less of your hair follicles are in the telogen phase at a given time, any factors that disrupt hair growth (like a stressful event) can prompt more strands to enter this stage.
12 Foods To Eat For Healthy Hair Growth
Stage 4: Exogen Phase
The final stage of hair growth is known as the exogen phase. During this phase, your hair detaches from the hair follicle and falls out. This allows new hair to grow in the follicle.
Exogen can last around 2-5 months. Shedding of as many as 100 strands daily during this phase is considered normal, especially if you maintain hair care habits like brushing and washing your hair.
A variety of lifestyle factors and tactics can encourage healthy hair growth.
Examine Your Hair Care Routine
Keep your hair care routine gentle. Try to avoid tight or damaging hairstyles like ponytails or extensions, which can stress the hair follicles. Also, consider minimizing the use of permanent hair color and hot tools, which can damage strands.
Eat a Balanced Diet
Improving your nutritional intake is also key for overall hair health. Vitamins and nutrients like biotin, vitamin E, zinc, and iron support hair follicle health and encourage faster growth. Supplementation can help prevent deficiencies if you're not getting enough of these in your diet.
Keep Your Scalp Clean
You may consider giving your scalp some extra support. For example:
- Keeping your scalp clean and healthy can promote hair growth by reducing the risk of scalp inflammation, infections, and dandruff.
- A self-care practice like regularly massaging your scalp might help stimulate hair growth, resulting in thicker and healthier hair.
- Stress management techniques might support hair growth. High stress levels trigger the production of the hormone cortisol, which can disrupt the hair growth cycle and lead to premature hair loss.
Try Over-the-Counter Medications
Over-the-counter (OTC) products can help with hair growth. Topical Rogaine (minoxidil) has been shown to stimulate hair follicles into the growth phase by increasing blood flow to the scalp. Anti-dandruff shampoos containing ketoconazole may also be helpful for hair regrowth.
Consider In-Office Treatments
If at-home habits and treatments don't seem to help hair growth, check with a healthcare provider about potential medical options. In-office procedures like microneeedling on the scalp, red light therapy, and platelet-rich plasma (PRP) may all be helpful for hair loss.
They may also recommend prescription medications like Propecia (finasteride) or spironolactone for female or male pattern hair loss.
Factors That Affect Hair Growth
Many health and lifestyle factors can affect the way that your hair grows. For example:
- Genetics: Researchers have identified certain genes that play a role in hair growth and the development of certain types of hair loss.
- Aging: Hair naturally becomes grayer and thinner with age, and you may notice that there aren't quite as many strands actively growing.
- Health conditions: Conditions like alopecia areata (which leads to bald patches), anemia (low red blood cell count), and autoimmune conditions like lupus can all interfere with hair growth.
- Hormones: Circ*mstances that trigger hormone fluctuations—like pregnancy, menopause, or thyroid conditions—often affect how hair grows.
- Stress: Emotionally or physically stressful situations, such as childbirth or cancer treatment, can disrupt or sometimes halt hair growth.
The speed of your hair growth cycle may fluctuate slightly at certain times throughout your lifetime. While growing out your hair may seem like it takes forever, most healthy hair grows roughly half an inch each month.
The hair growth cycle includes four stages: anagen, catagen, telogen, and exogen. During these phases, hair is actively growing, transitioning, resting, or shedding. Factors like genetics, age, medical conditions, hair care habits, and stress can all affect hair growth.
With the guidance of a healthcare provider, remedies for encouraging hair growth include lifestyle changes, topical treatments, in-office procedures, and prescription medications.
