Does Hair Grow Faster in Summer? Myth VS Science

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Introduction

You might have heard someone claim, “My hair grow faster in summer,” or maybe you’ve even noticed it yourself. But is there any truth to that? Or is it just another one of those seasonal myths?

Understanding how hair grows and what influences its cycle can help clear up the confusion. In this blog, we’ll dive into the science of hair growth, explore how seasonal changes like summer can affect it, and share some practical tips to keep your hair healthy all year long.

How Hair Growth Works

Hair growth follows a natural cycle with three main phases:

  1. Anagen (growth phase): This is when your hair is actively growing. At any given time, about 85% to 90% of the hair on your scalp is in this phase, which can last anywhere from 2 to 7 years.
  2. Catagen (transition phase): This is a short phase lasting about 2 to 3 weeks, during which the hair follicle starts to shrink.
  1. Telogen (resting/shedding phase): This phase lasts around 2 to 4 months. After this, the hair falls out, and the cycle restarts.

On average, hair grows about 1 to 1.25 cm per month (approximately half an inch). However, this growth rate can vary based on factors like genetics, age, diet, health, and hormonal balance.

Factors influencing hair growth

  • Genetics: Determines how long your anagen phase lasts.
  • Hormones: Androgens like DHT affect hair density and thickness.
  • Diet and nutrition: Nutrients like protein, biotin, iron, and vitamin D play a key role.
  • Overall health: Stress, illness, or medication can interrupt the cycle.

The Role of Seasonal Changes on Hair Growth

Seasons do influence our body in various ways, and hair is no exception.

  1. Hormonal Shifts

Studies indicate that seasonal changes can influence our hormone levels. For example, hormones like prolactin and melatonin tend to fluctuate with varying light exposure. While these hormones can indirectly affect hair growth cycles, the evidence isn’t entirely conclusive just yet.

  1. Increased Sunlight and Vitamin D

Getting some sun helps your body produce vitamin D, which is crucial for the cycling of hair follicles. Some research has even linked a lack of vitamin D to hair loss (1). During the summer months, we naturally soak up more sunlight, which could be beneficial for our scalp health and the functioning of our hair follicles.

  1. Scalp Blood Circulation

Warmer weather can boost blood flow to the scalp. Improved circulation means that more nutrients can reach the hair follicles, potentially encouraging growth. However, this doesn’t necessarily mean your hair will grow faster; it just creates a healthier environment for it to thrive.

Close-up of sunlight shining on a healthy scalp with glowing lines symbolizing vitamin D absorption

Scientific Studies on Hair Growth and Summer

Several studies have explored seasonal effects on hair growth:

  • A 1991 study published in the British Journal of Dermatology tracked hair growth in 14 healthy men over 18 months. It found that the number of hairs in the anagen phase peaked in March and hit its lowest point in September (2).
  • Another study from 2014 observed that seasonal shedding tends to increase during late summer and early autumn (3). This supports the idea that more hairs transition into the telogen phase in summer, which might explain why some people notice more hair loss during this period.

Key Takeaways from Research:

  • Contrary to popular belief, hair doesn’t necessarily grow faster in the summer.
  • You might notice more hair shedding as summer winds down.
  • Sunlight and good circulation can play a role in keeping your hair follicles healthy.

However, it’s worth noting that the studies conducted so far are relatively small and primarily focused on men. We definitely need more diverse and larger studies to draw stronger conclusions.

Other Factors That Can Affect Hair Growth in Summer

  1. Sweating and Scalp Hygiene

When the weather heats up, so does our sweating. A sweaty scalp can lead to buildup, clogged follicles, and itchiness if we don’t wash it properly. While this doesn’t directly slow hair growth, it can impact the health and comfort of your scalp.

  1. Changes in Diet and Hydration

Summer usually means an influx of fresh fruits, veggies, and plenty of fluids. Staying hydrated is key for overall health, including the health of your hair. On the flip side, dehydration can leave your hair looking brittle and dry.

  1. Sun and UV Damage

Too much sun can harm the outer layer of your hair (the cuticle), making it weak and more susceptible to breakage. While this doesn’t affect growth at the roots, it can make your hair look thinner or shorter because of the damage.

Flat lay of hair growth foods including eggs, berries, nuts, spinach, salmon, and avocados on a rustic wooden table

  1. Outdoor Activities

Spending time in pools or the ocean and soaking up the sun can dry out both your scalp and hair. Chlorine can strip away natural oils, and frequent washing can wash away the sebum that protects your scalp.

Tips to Support Healthy Hair Growth Year-Round

Even if hair doesn’t grow faster in summer, you can still maintain and support its health:

  1. Balanced Diet

          Eat a diet rich in:

  • Protein: Since hair is primarily made of keratin.
  • Iron and zinc: Essential for healthy follicle function.
  • Vitamin D: Plays a role in regulating the hair growth cycle.
  • Biotin: Aids in strengthening your strands.

  1. Scalp Care

  • Wash regularly to remove buildup.
  • Use mild shampoos.
  • Massage the scalp to improve circulation.

  1. Sun Protection

  • Wear hats or scarves in direct sun.
  • Use leave-in products with UV filters.
Top-down view of summer hair care essentials including shampoo, conditioner, UV protection spray, and a wide-brim hat on a yellow towel

  1. Stay Hydrated

Make sure to drink plenty of water throughout the day. Staying hydrated helps keep moisture levels balanced in both your hair and scalp.

  1. Professional Help

If you notice sudden or severe hair loss, consult a dermatologist. Hair loss may be linked to underlying health issues, not just the weather.

FAQs

Does sweating more in summer help hair growth?
Not really. While sweating does boost blood circulation, too much sweat can irritate your scalp. Keeping it clean is key to avoiding buildup.

Can sun exposure boost hair growth naturally?
Sunlight does help your body produce vitamin D, which can support your hair follicles. However, too much sun can actually damage your hair.

Does humidity affect hair growth rates?
Humidity impacts hair texture rather than growth rate. It might make your hair frizzier or flatter.

 

Are hair growth supplements more effective in summer?
Nope. Supplements work the same no matter the season. They’re only beneficial if you have a deficiency.

How does scalp health change with seasons?
In summer, you’ll notice more oil, sweat, and buildup, while winter can bring dryness and flakiness. It’s important to adjust your hair care routine according to the season.

Conclusion

So, does hair grow faster in the summer? Science says not really. While warmer weather, sunlight, and improved blood flow can support a healthy scalp, they don’t significantly speed up the hair growth cycle. In fact, you might notice more hair shedding as summer comes to a close.

Hair growth depends on many factors: genetics, diet, scalp care, and overall health. Consistent care — not the calendar — is what truly supports long-term hair health.

Circular illustration of a woman caring for her hair in each of the four seasons—winter, spring, summer, and fall—with seasonal backgrounds and attire.