How Long Does It Take For Hair To Grow Back? Hair is made of protein strands. Human hair grows continuously in a cycle of growth and rest, which is made up of three phases. Anagen is the growth phase and can last anywhere from two to eight years. Hair grows an average of 0.5 inches per month, or 6 inches in a year.

Catagen is the second phase, which involves the degradation of the hair follicle over a period of two to four weeks. Lastly, telogen is a phase involving rest and can last two to four months. The normal shedding of hair occurs after the telogen phase when the new anagen phase begins to grow a new hair shaft.

On average, up to 100 hairs are shed each day during this process, which can be seen in the shower drain or hairbrush. It is important to remember that all the hair follicles on your body are in various different points of the hair growth cycle and that no more than 10% of follicles are in the telogen (resting) phase at one time (1).

Factors Affecting Hair Growth and Loss

How Long Does It Take For Hair To Grow Back

As mentioned previously, hair grows an average of 0.5 inches per month and 6 inches per year. There are various factors that affect the growth of hair in addition to the temporary or permanent loss of hair.

These factors will contribute to the speed at which your hair grows. Later in this article, we will discuss ways to support hair growth, which may just be a result of optimizing the factors below.

Read Also: Best Hair Growth Products for Men.

Health Conditions and Medications

There are several different skin or hair conditions that directly affect hair growth. Several life scenarios can also result in hair loss, such as having a baby, undergoing cancer treatment, losing 20 pounds or more, and major illness or surgery.

Other conditions such as thyroid disorders and anemia can result in hair loss. Some medications or chemical exposures can also cause loss of hair (2).

Hair Care

If you have ever been a victim of over-bleached hair, it may not be a surprise to you that hair damage can result in hair loss. Even wearing your hair in a style that is tight can result in a hair loss condition called traction alopecia.

Examples of other bad hair habits include shampooing the length of your hair, brushing your hair while it is wet, dry your hair by rubbing it with a towel, and skipping conditioner. These habits may lead to damage which may lead to, you guessed it – hair loss (3).

Nutrition

Some vitamin deficiencies can lead to hair loss, and one of the easiest ways to optimize your hair growth is to ensure you are consuming a well-balanced diet. If you are not able to get enough iron from foods such as red meats and dark green, leafy vegetables, your physician may recommend an iron supplement (4).

Omega-3, which can be found in fish and seafood, has also been proven to aid in hair growth (5). Some specialized hair vitamins may be composed of a larger amount of one ingredient, so some dermatologists may recommend a simple multivitamin as opposed to one marketed for hair growth. Always get the advice of a licensed physician prior to starting a vitamin supplement regimen.

Hormones

Hormones have a huge impact on the hair cycle and hair follicle itself. Sex hormones, known as androgens, include testosterone and dihydrotestosterone and have been proven to influence hair growth.

Research is also being done to discover the role of other hormones on hair growth, such as estradiol, progesterone and prolactin (6).

Age

Age-related hair loss can be due to a variety of underlying reasons. The hair life cycle shortens as you age, and tends to result in finer hair. Sex hormones, which we know contribute to hair growth, decrease over the lifespan and are decreasingly available to restore the hair follicle to grow hair.

For example, menopause in women tends to be associated with hair thinning and loss due to the lack of new growth over time. Once the hair fibers become thinner and drop out, they unfortunately never regenerate (7).

Genetics

There is no doubt that genetics have an influence over hair texture, density, color, and even length. We can see the differences in hair types among different ethnicities that are due to genetics. There are also hereditary disorders that cause hair loss. Some people are simply genetically predisposed to hair loss (8).

Timing

According to various research, hair grows faster in warmer months of the year. According to a study published by the British Journal of Dermatology, the rate of hair growth steadily increased from March to July until it reached a peak of 60% faster than the growth rate in the winter months (9).

Stress

Did you know that stress could cause hair loss in both men and women? According to science, we have about 3-types of hair loss that are connected with high-stress levels: trichotillomania, telogen effluvium, and alopecia areata.

Telogen effluvium is a process when a large amount of stress causes numerous hair follicles to go into a pause phase (catagen).

Alopecia areata is thought to be caused by a variety of factors, one of which being stress. This condition is an autoimmune disorder where the hair follicle is attacked by the body’s immune system and ultimately causes hair loss (10)

Trichotillomania is the irresistible strong desire to pull hair out, which can occur as a way of coping with emotional distress.

FAQs on How Long Does It Take For Hair To Grow Back

How long does it take for hair to grow back after hair loss?

How long does it take for eyebrow hair to grow back?

Eyebrows are an important part of one’s facial features. However, grooming them can often pose a difficult task. The hair growth cycle is 3-4 months for eyebrows. Caution should be used to prevent over-plucking your eyebrows, as this may lead to damage and scarring to the hair follicle and result in the inability to grow the hair back.

There are medications that may help with regrowth, one being Latisse. Latisse (Bimatoprost) is a prescription topical medication that is traditionally used to stimulate eyelash growth but has also been shown to aid in eyebrow growth as well (4).

How long does it take for hair to grow back after chemo?

Chemotherapy is a powerful classification of drugs that attack rapidly growing cancer cells. Unfortunately, these drugs also attack the rapidly growing cells that are present in the hair root, causing hair loss. Some specific kinds of chemo can cause more hair loss than others (11).

Chemo can cause hair loss to the eyebrows, underarms, and pubic area among other areas, not just the hair on the scalp. However, hair loss associated with chemotherapy is temporary in the majority of cases.

It may take three to six months after treatment stops to begin noticing hair growth. Additionally, your hair may be a different color and/or texture compared to the hair that you had prior to chemo.

How long does it take for hair to grow back after hair loss?

The timeline for hair growth after loss varies tremendously depending on the type of hair loss you are experiencing. The general rule of thumb is that hair grows approximately 0.5 inches per month and 6 inches per year.

However, some forms of hair loss are permanent and may not respond to treatment. According to the American Academy of Dermatology, the first step should be to get an accurate diagnosis from a dermatologist or hair loss specialist (12).

From there, the physician will analyze your factors and develop an individualized care plan with you to optimize your hair growth opportunity.

  • How long does it take for leg hair to grow back?
  • How long does it take to grow 2 inches of hair?
  • How can I make my hair grow faster?

Does hair grow back faster after cutting it?

Hair grows faster when its healthy. Hair also grows from the root at the scalp versus the ends. So while technically hair cutting doesn’t directly cause it to grow faster, regular trims prevent the ends from splitting and promote healthier hair overall.

It also prevents larger portions from having to be cut off per trim, which allows you to maintain the maximum amount of length. Hair without split ends also looks visually healthier and fuller.

Supporting Hair Growth

Hair grows faster when it is healthy. Hair also grows from the root at the scalp versus the ends. So while technically hair cutting doesn’t directly cause it to grow faster, regular trims prevent the ends from splitting and promote healthier hair overall.

It also prevents larger portions from having to be cut off per trim, which allows you to maintain the maximum amount of length. Hair without split ends also looks visually healthier and fuller.

Treatment Options

References

  1. https://ishrs.org/2012/08/27/hair-loss-and-the-hair-growth-cycle/
  2. https://www.aad.org/public/diseases/hair-loss/treatment/diagnosis-treat
  3. https://www.aad.org/public/diseases/hair-loss/causes/hairstyles
  4. https://health.clevelandclinic.org/5-ways-to-get-overplucked-eyebrows-to-grow-back/
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6164340/
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7432488/
  7. https://health.clevelandclinic.org/your-guide-to-aging-hair/
  8. https://pubmed.ncbi.nlm.nih.gov/5173315/
  9. https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2133.1991.tb00423.x
  10. https://www.mayoclinic.org/healthy-lifestyle/stress-management/expert-answers/stress-and-hair-loss/faq-20057820
  11. https://www.mayoclinic.org/tests-procedures/chemotherapy/in-depth/hair-loss/art-20046920
  12. https://www.aad.org/public/diseases/hair-loss/treatment/diagnosis-treat