Does Hair Shed More in the Summer? Answers from an Expert

If you’ve noticed a few more strands in the shower drain during the summer, you’re not losing your mind. Does hair fall out more in summer? It’s possible. 

Some women report experiencing more shedding during the warm summer months. Research shows a potential seasonal link, too.  

In this article, we’ll discuss the link between hair loss and the seasons, the research behind it, and what you can do about summer shedding. 

Researchers at Johns Hopkins University and Washington University compiled 12 years’ worth of Google trends data to see if there was any connection between seasonal changes and hair loss.

The researchers looked at the trends data from eight English-speaking countries with high search rates for the term “hair loss,” and compared the data across seasons and months 

They discovered that across all eight countries, the results were consistent. People searched Google using phrases related to hair loss more frequently in the summer and fall. 

But what causes this seasonal hair loss pattern — and should you be concerned? Or is this search data just a coincidence? Let’s get into it. 

Many animals, from dogs and cats to monkeys and horses, shed seasonally. But do humans shed hair in the summer? Yes, it’s definitely a human thing too. 

“Seasonal hair shedding is well-documented,” says Asmi Berry, DO, FAAD, a board-certified dermatologist practicing in New York City. “Many people experience increased shedding during the summer because a higher number of hair follicles enter the telogen (resting) phase in the warmer months.” 

Studies in men and in women have also found that the greatest amount of telogen hairs typically occur at the end of summertime and the start of the fall.

Telogen hairs refer to the resting phase of the hair growth cycle. At the end of the telogen phase, the hair enters the shedding phase where it releases from the hair follicle to prepare for new hair growth.  

An older study in men showed that the peak months for hair shedding are August and September. The study also found that the peak time for the anagen phase of the hair cycle, during which hair growth occurs, is at the beginning of spring.  

The authors of a 2009 study suggest that a potential biological reason for late summer hair fall is to protect the scalp from harmful UV radiation from the summer sun. Meanwhile, having lower shedding during the winter months may serve to keep your head warm when it’s cold out. 

Changes to the hair cycle during the summer months could also be related to longer periods of sunlight, called the photoperiod, and increases in temperature. In horses and goats, there’s a link between longer photoperiods and higher temperatures and hair growth. 

According to experts, there are many potential causes of summer hair shedding.

Does Hot Weather Cause Hair Loss? 

“Factors like heat, humidity, and sun exposure can all play a role in increased shedding during the summer months. Heat and humidity can create weaker hair strands and follicles, leading to more breakage and shedding,” notes Michele Green, MD, a board-certified dermatologist practicing in New York City.

Some research has actually found that hair becomes stiffer and more brittle in the summer, which could boost the risk of breakage — and shedding.

Sunlight  

When it comes to summer hair shedding, the sun is not your friend. “Exposure to harmful UV rays can also damage hair follicles, resulting in hair thinning and shedding,” Dr. Green adds. 

Due to longer summer days and warmer temperatures promoting outdoor activities like going to the pool and the beach, we’re definitely exposed to more sunlight in the summer. 

UV radiation from sunlight has long been known to be harmful to hair. Exposure to UV radiation may boost oxidative stress in the hair follicle, damaging your hair and potentially leading to breakage. 

The impact of UV radiation is more pronounced in people with lighter colored hair, including those with gray or white hair. That’s because these hair tones have less melanin, a pigment that protects against sun damage.

Other Summer-Related Factors 

Dr. Berry also points out the impact of the summer environment on scalp health. “Environmental stressors like UV radiation, increased sweating, and inflammation from sunburns, chlorine, or saltwater can disrupt the scalp environment and contribute to shedding,” she says.

At the end of the day, all of these factors can cause scalp irritation or itching. This can lead to scratching, which can boost hair shedding and loss.

Non-Seasonal Reasons for Hair Loss 

Lastly, we shouldn’t forget the other common things that contribute to hair loss in general, including genetic, dietary, and lifestyle factors. 

While they’re not summer-specific, they can also influence summer hair shedding.  

When it comes to preventing summer hair shedding, the experts we consulted offered a variety of insights. Taking steps to protect your hair and scalp from the environment were front and center.

Sun Protection 

“Women should protect their hair from the sun’s harmful rays by using a hat or scarf to cover their hair and prevent UV damage,” suggests Dr. Green. 

Dr. Berry agrees. “It's important to protect your scalp like you would your skin,” she says. “Minimize UV exposure to the scalp by wearing a hat or using a scalp-specific SPF spray. After swimming, rinse hair thoroughly to remove chlorine or salt, which can damage the hair shaft.”

Additional Hair Loss Prevention Tips 

Here are a few tips to help boost hair health at any time of the year: 

• Consider your diet. “Maintaining a balanced diet with adequate protein and micronutrients is important for hair growth year-round,” says Dr. Berry. Try to ensure you’re getting enough of nutrients that are important for healthy hair growth, like protein, iron, vitamin D, and biotin.

• Be gentle. When it comes to hair care, gentler is better. For example, massage shampoo into your scalp gently. Similarly, try not to pull or tug on your hair too much while styling it. And never style it while it’s wet.

• Avoid heat styling. Heat can damage hair, so try to limit your use of things like blow-dryers, flat irons, or curling irons.

• Change your style. Tight hairstyles, like ponytails, braids, or buns can damage hair follicles, so consider changing your hairstyle up to prevent this.

• Hydrate hair. Keeping your hair moisturized can prevent dryness and breakage. In addition to drinking enough water, you can improve hair hydration by choosing moisturizing hair products that are right for your hair type.

• Reduce stress. Psychological stress is a trigger for a type of hair shedding called telogen effluvium. Finding ways to reduce stress in your everyday life can help limit this kind of hair loss. 

Let’s cover some treatments for hair loss in summer (or any season for that matter) below.

Minoxidil 

When it comes to female hair loss, you may hear a lot about minoxidil – and for good reason. 

“Topical minoxidil is an excellent FDA-approved hair loss treatment that works to strengthen hair follicles, increase hair thickness, and prevent shedding,” says Dr. Green. “Oral minoxidil can also be prescribed off-label to reduce shedding and prevent hair [loss].”  

Topical minoxidil is available over the counter as a 2% solution or 5% foam while the oral version comes as a tablet. 

Minoxidil works by signaling your blood vessels to open, allowing more nutrients and oxygen to flow to the hair follicles. It also lengthens the growth phase of the hair growth cycle.

We’ve written more about what to expect from minoxidil in our Complete Guide to Minoxidil for Female Hair Loss.

Spironolactone 

Spironolactone is a medication that has also been used as an off-label treatment of hair loss in women. It works by preventing the conversion of testosterone to dihydrotestosterone (DHT) (a male sex hormone linked to pattern hair loss) and can help to improve hair density and reduce hair loss in women.  

“Women experiencing hormonal fluctuations, especially due to conditions such as PCOS and menopause, can take oral spironolactone to regulate their androgen hormones and reduce shedding,” notes Dr. Green.

Finasteride 

Another medication that may be used off-label for hair loss in postmenopausal women is finasteride. Similar to spironolactone, it works by preventing testosterone from being converted to DHT.

Platelet-Rich Plasma (PRP) 

If medications aren’t effective, Dr. Green also says that a treatment called platelet-rich plasma (PRP) injections may be beneficial.

“PRP is taken from a patient’s blood and is rich in epidermal growth factors and proteins. When injected into the scalp, PRP works to stop hair shedding, increase hair density, and stimulate hair growth. Individuals often need an initial series of PRP treatments, followed by regular maintenance sessions to keep shedding at bay and promote healthy, beautiful hair,” she says.

Seasonal hair shedding, particularly during the summer months, is pretty normal. But, if you’re concerned about the amount of hair you’re losing, or you are shedding year-round, it may be worth looking into an underlying cause. 

Let’s recap what we know about summer shedding:

• Shedding can happen anytime of year, but you might notice more in the summer. Sun exposure, sweat, and extra washing can stress your scalp and trigger more shedding than usual.

• UV rays can damage your hair making strands weaker. That makes them more prone to breakage. 

• Summer shedding is usually temporary and preventable. Keep your hair healthy by wearing hats, applying UV protection, and using moisturizing products.

If shedding seems excessive or doesn’t slow down, talk to a healthcare provider. It could be a sign of female pattern hair loss. 

Your local dermatology practice is a great place to start. Dermatologists specialize in diagnosing and treating conditions of the skin, hair, and nails.

Want to learn more about potential hair loss causes and solutions? Read our Female Hair Loss Condition Guide and our guide on How To Prevent Hair Loss in Women.