Does Sun Light Cause Cold Sores?

Does Sun Light Cause Cold Sores?
Michele Emery, DNP
Medically reviewed by Michele Emery, DNP Written by Our Editorial Team Last updated 5/21/2019

There’s a lot to look forward to during the summer. With sunnier weather, people are in better moods and up for adventurous hikes, beach days and afternoons at the park. But if you have oral herpes, there’s one simple thing you should watch out for—the sun. Sun light does cause cold sores, and if you're not careful, overexposure may trigger an outbreak. Most studies estimate that between 50% to 70% of the population have HSV-1, the virus that leads to oral cold sores. Though the virus is one of the most common in the world, there’s still plenty of misinformation on the web about how to deal with it. To make the warmer months easier for those affected by HSV-1, we’ve put together a guide on how to prevent sun light from cold sores or making your outbreak worse.

How Does Sun Light Cause Cold Sores?

The sun is one of many triggers for cold sores that include everything from fatigue, illness and hormonal changes to even anxiety in some cases. Summer days mean more time outside, which subsequently increases your chance of having your skin damaged by the sun. The sun exudes ultraviolet (UV) light rays which go unseen by the eye but impact your body. Although these rays cause people to produce beneficial nutrients like Vitamin D, it also wreaks havoc on the skin when it's absorbed. Lips—the area where most oral HSV-1 cold sores originate—are especially vulnerable to UV light rays because they don’t have melanin. If you are already prone to cold sores, you should be particularly careful and learn about ways to stop sun damage before it happens.


You have probably been told from a very young age how vital it is to apply sunscreen. A certain song comes to mind. But its importance can’t be understated—especially if you have cold sores. Before going out, apply an SPF 30+ sunscreen around the area of your mouth. If you’re concerned about titanium dioxide and zinc, there are plenty of organic options like Badger, Alba Botanica and Naturopathica

Lip Balm

When the sun is out, the climate tends to be dryer. In order to mitigate the effects of a dry climate on your lips, you should regularly apply lip balm to moisturize and protect your lip skin. There are even lip balms that are specifically meant to help prevent—and treat—a cold sore outbreak like Herpecin L. If you're going to be in the sun frequently, moisturizing all your skin is a good pro-tip, in general. We have stuff for that. 

Tiger Grass

In recent years, Tiger Grass has grown in popularity. Containing ingredients like Centella Asiatica leaf water, raspberry leaf extract and panthenol, Tiger Grass creams moisturize the face. Even if your skeptical of the Tiger Grass craze, Dr. Jart’s Cicapair Tiger Grass moisturizer also contains SPF 30+ sunscreen which guarantees increased protection from the sun.

Aloe Vera

Even if you try your best to protect yourself from the sun, there are times when you may forget and end up with a brutal sunburn. That’s where aloe vera comes in. Aloe vera is a plant that has been used by man for thousands of years to treat a multitude of skin conditions. Today, it's a sunburn relief go-to that's backed by science. Apply it to stop the sunburn from further irritating and damaging your skin. However, it's best to be careful and take the time to truly read the ingredients. Don’t buy any creams that also contain lidocaine, petroleum and benzocaine because those stop heat from leaving your skin and may make things worse. Additionally, you should look for products that are one hundred percent aloe vera and keep them refrigerated for the best results.


This may seem obvious, but sometimes the best life hacks are incredibly basic. In the sunny season, make sure to stay hydrated. Though there’s contradictory research about whether water has a miraculous amount of health benefits, there’s a general consensus that being dehydrated can make skin damage worse. It’s recommended that you drink anywhere from eight to ten ounces of H20 on a daily basis.

Spend Less Time In The Sun

Though there’s no shortage of articles online warning people about the danger of sunbathing, people are still inexplicably drawn to the allure of being a bronzed god or goddess. According to the CDC, skin cancer is the highest form of cancer in the U.S. Especially if you are prone to cold sores, you shouldn’t go out of your way to harm your skin by basking in UV light. Can you go in the sun with a cold sore? Of course! Does going out in the sun mean you'll absolutely have an outbreak? Absolutely not. But be smart about it. Little things like always wearing a hat, staying in the shade and not sitting in the sun for too long can go a long way in preventing skin irritation.

Why Valtrex Is Your Most Reliable Option

Regardless if you have been diagnosed with HSV-1 or not, you should be smart about sun protection. While protecting yourself from a severe sunburn and skin irritation can stop a cold sore from being triggered, there are a myriad of different ways in which they can still happen. If you do end up having a cold sore outbreak, you should rely on scientifically verified and tested methods like the anti-viral medication Valtrex to stop the infection from multiplying and going to other places of the body. We swear by the stuff.

If you want to read more about getting a healthier lifestyle, check out our blog.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.