Sunlight is one of the most effective natural sources of vitamin D. Research suggests that vitamin D deficiency may be associated with hair loss. Therefore, exposing hair to the sun could be beneficial for scalp and overall hair health. However, while vitamin D is important for healthy hair, exposure to UV radiation through sunlight can cause serious hair damage. [1]
What are the effects of the sun on hair?
Even in small amounts, the sun affects the hair's life cycle thanks to vitamin D, allowing keratin to grow faster and stronger. [4] Another significant effect of sunlight on hair is weakening of the hair caused by protein damage. This occurs not only through direct contact with UV rays, but also through the sun's production of harmful molecules called reactive oxygen species (ROS), which damage hair. [3]
How do sun rays affect hair structure?
Photochemical damage to hair leads to the degradation and loss of hair proteins, as well as the deterioration of hair pigment. This can lead to problems such as dryness, loss of color, loss of shine, hardness, and brittleness. [2]
Does sea and pool water damage hair?
Salty seawater and the sun's ultraviolet rays are just as damaging to hair as the chlorine in swimming pools. Substances like salt and chlorine quickly penetrate hair strands and weaken their structure over time. Therefore, washing your hair with clean water after swimming in the sea or pool helps minimize the damage. [5]
Does hair loss increase in summer?
Research shows that hair loss increases particularly during the summer months, most notably in August and September [6]. UV exposure from sunlight can slow hair growth by affecting the hair cycle. Increased light damages structural hair proteins, while changes in melatonin and hormones can weaken follicles and increase hair loss. [7]
Basic Methods for Protecting Hair in Summer
There are simple steps you can take to protect your hair from the harmful effects of the sun in summer:
- Protect your hair from direct sun by covering it,
- Avoid heat styling,
- Choose shampoos and conditioners that moisturize your scalp,
- Avoid over-washing your hair.[9]
Ways to physically protect hair from the sun
Covering your head when going outside is one of the most effective ways to protect yourself from the sun's harmful effects. Use a light scarf, a wide-brimmed hat, or a cotton bandana [9].
Why is it important not to go out in the sun with wet hair?
Prolonged exposure to wet hair is thought to be as damaging as blow-drying at high temperatures. While blow-drying can cause more surface damage, research suggests that using the device continuously from a distance of 15 cm (6 inches) is less damaging than drying hair naturally. [10]
Which products should be used before sun exposure?
Shampoos and preparations containing tannic acid, gallic acid, and caffeic acid have been proven to protect the scalp by blocking the passage of UV rays and also help the hair regenerate itself [8]. In addition, UV-protective sprays or hair serums are also recommended [9].
Extra Tips for Hair in Summer
In addition to consuming enough water, your diet should include some hair-friendly foods:
- Biotin â for hair growth
- Omega-3 fatty acids â to nourish the scalp
- Zinc and Iron â to prevent hair loss [9]
Additionally, a weekly scalp exfoliation helps promote strong hair growth by removing buildup and improving circulation. In addition to exfoliation, a massage using coconut, almond, or tea tree oil, depending on your scalp type, can deeply nourish the roots. [9]
How to protect hair ends?
Environmental factors can cause hair strands to become damaged and split at the ends, leading to split ends. To prevent this, be sure to get regular haircuts and gently comb your hair. [12]
Why should you shower with lukewarm water instead of hot water?
Washing hair with hot water dries out the scalp and can trigger eczema. Hot water damages the scalp and makes hair breakage easier. Therefore, hair should be washed with lukewarm water. [13]
How does staying away from the hair dryer affect the hair?
High temperatures during the summer months can make already sun-damaged hair even more vulnerable. Tools like straighteners, curling irons, and dryers can exacerbate this damage. Therefore, reducing the frequency of heat styling and always applying a heat protectant spray is important for hair health. [14]
The sun's UV rays can damage the keratin protein, which gives structure to the scalp and hair. Furthermore, the scalp is more susceptible to sunburn and damage, which can accelerate skin aging and increase the risk of skin cancer. Covering your head when exposed to the sun, using hair products with UV filters, and rinsing your hair after swimming in the pool or ocean are effective measures you can take to protect your hair's health [11].
Source:
1. Is Sunlight Good for Your Hair? Evidence Review 2025 (14.4.2025), Dr. Ahmad Moussa (FRCS)
2. UV damage of the Hair (November 2008), Klaudija Sebetic, Ines Sjerobabski Masnec, Vlatka Cavka, Darko Biljan
3. Effects of solar radiation on hair and photoprotection, Short Review, Michelli F. Dario, André R. Baby, Maria Valéria R. Velasco
4. CENTER CLAUDERER, THE BENEFITS AND HARMFUL EFFECTS OF THE SUN ON YOUR HAIR, Jean-François Cabos
5. Dr. Cemalettin EkmekçioÄlu - Chlorine in Pools is Harmful to Hair
6. Wiley Online Library - Seasonality of hair loss: a time series analysis of Google Trends data 2004â2016 (19 October 2017), EY Hsiang, YR Semenov, SG Kwatra
7. Frontiers - Melatonin Regulates the Periodic Growth of Cashmere by Upregulating the Expression of Wnt10b and ÎČ-catenin in Inner Mongolia Cashmere Goats, (09 July 2021)
8. Protection and Restoration of Damaged Hair via a Polyphenol Complex by Promoting Mechanical Strength, Antistatic, and Ultraviolet Protection Properties by Hyun Jeong Won, Tae Min Kim, In-sook An, Heung Jin Bae, and Sung Young Park, (9 July 2023)
9. Sarvodaya Healthcare - Summer Hair Care Tips: Protect Your Scalp and Hair from Heat and Humidity (May 07, 2025), Dr. Shruti Kohli (Senior Consultant â Dermatology)
10. Hair Shaft Damage from Heat and Drying Time of Hair Dryer, Yoonhee Lee, MD, Youn-Duk Kim, MD, Hye-Jin Hyun, MD, Long-quan Pi, Ph.D., Xinghai Jin, MD and Won-Soo Lee, MD, (Nov 03, 2011)
11. Everyday Health - How to Protect Your Hair Against Sun Damage, By Christine Byrne, (July 25, 2024)
12. What's Good for Split Ends? Dr. Ahmet GĂŒldĂŒ, Dermatology (Skin Medicine), (18.11.2024)
13. Hair Washing Frequency - Prof. Dr. Zekayi Kutlubay, CerrahpaĆa Faculty of Medicine, Department of Dermatology and Venereology
14. Tulip Hospital â Hair Fall Increases in Summer? Here's Why
