Can Red Light Therapy Cause Cold Sores?

You might have heard something about red light therapy and its potential benefits for skin care, anti-aging, etc. If you didn’t, then we will share some insights. Red light rays can penetrate deep into the skin and may maintain healthy blood pressure. Good blood pressure may deliver oxygen and nutrients around the body and improve your skin, hair, nails, and overall health.

However, there might be some side effects. So, can red light therapy cause cold sores? Every treatment, if overused, may cause health consequences. We should not ignore the recommendation for using such near-infrared, infrared light therapy devices, like red light beds, lamps, etc.

In order to eliminate your doubts about whether RLT causes cold sores, we will talk about the relationship between them.

Keep reading to find out more!

What Are Cold Sores?

The term “fever blisters” is another name for cold sores. This condition may be itchy and painful.

Cold sores are fluid-filled blisters that usually appear around the mouth. Once the blister breaks, it forms a scab and lasts for several days. This condition may be spread from person to person while making close contact, like kissing.

The blisters are caused by herpes simplex virus (HSV) type 1 and type 2. In both cases, they may affect the mouth or genitals during intercourse. Cold sores may appear if you have a weak immune system or some kind of irritation.

Potential causes of cold sores are viral infection, hormonal changes, stress, immune system changes, skin injury, external infection, and exposure to sunlight and wind.

The last cause may be related to red light therapy (RLT).

What are Cold Sores?


Can Red Light Therapy Cause Cold Sores?

Red light therapy may help your skin to regenerate and rejuvenate. It may have a positive effect on the skin cells, allowing them to recharge with energy and improve skin condition. They initiate collagen and elastin production, the two main proteins in your body responsible for healthy skin maintenance.

On the other hand, cold sores are a kind of skin infection caused by inflammation or close contact with an infected person.

A study shows that RLT may heal oral and labial herpes simplex viruses. Red light therapy may also decrease the pain caused by cold sores and help you get over them faster.

By this fact, we may say that red light does not cause cold sores, but the opposite. It may help them heal faster and make the healing process less painful.

How does red light affect cold sores?

Red light rays may promote biostimulation in the tissues. This process begins at a cellular level and involves a photochemical reaction in the cells.

The red light rays may address symptoms of diseases and underlying causes. Red light therapy may also be an effective therapy for treating cold sores.

The cold sore healing process begins with energy stimulation in the mitochondria. The cells start to produce more energy, which is further used to perform multiple functions like damage protection, repair, and replication.

Furthermore, some studies have pointed out that red light therapy may reduce inflammation and increase collagen production. At the same time, it may improve blood circulation and enable blood flow in all parts of the body properly, delivering oxygen and nutrients.

The number of side effects caused by red light therapy is pretty low. You can use a red light device at home, 10 to 20 minutes daily, three to five times a week, for treating cold sores.

Do not exceed the recommended time. Red light overuse may cause unwanted side effects if exposed too long.

Do not practice UV rays for treating cold sores!

UV rays are spread by the sun and are a reason for causing cold sores. Long UV exposure can increase the infection and recurrence of HSV outbreaks.

Minimize UV exposure if you have cold sores. Use sunscreen and minimize the time going out when the sunlight is strongest. Many studies have suggested that UV light can increase the risk of HSV recurrence and prolong the healing time.

Red Light Therapy and cold sores


3 Studies About the RLT Benefits for Treating Cold Sores

Study 2009

This study involved 69 patients with mouth ulcers. These people were exposed to only one therapy session. The result showed improvement in mouth ulcers

Another study the same year involved 232 patients. Those people had mouth lesions and saw improvements after multiple red light therapy sessions. The studies have shown that red light therapy showed a significant period among the flare-ups.

Study 2013

This study focused on herpes around the mouth area. This study divided the patients into two groups. The first group was exposed to red light treatment, while the other group was treated with a placebo.

The group exposed to red light therapy showed a better effect with a reduced healing time of an average of 129 hours, while the placebo group needed approximately 177 hours to see the same effects.

Study 2018

Three studies this year have provided that red light therapy sped up the healing period and reduced the pain caused by oral herpes lesions. These studies have measured the time needed to resolve the herpes lesions and their complete re-epithelialization, and the time required for the lesions to crust over.

Direct application of 1072 nanometers of RLT for three minutes reduced healing time by 48 to 72 hours. These studies concluded that direct red light exposure could accelerate the healing time of cold sores caused by herpes simplex.

The patients were pretty satisfied with the treatment, reporting that it is relatively simple and affordable for home use, and denied any side effects caused by the red light therapy.

These studies were made with selective medicine based on evidence to determine if low-level light therapy can help in treating oral herpes simplex lesions.


So, can red light therapy cause cold sores? The answer is no. Many studies have shown the opposite.

Low-level light therapy may speed up the healing time and help you get over the cold sores faster. The effects are still not 100% proven, but current studies with medical evidence have shown that red light therapy shows faster healing results than placebo therapy.

Do not exceed the time exposed to red light. There are no serious side effects reported still, but it may not be good to overuse the device.

Leave a Comment