Red light therapy for painful and embarrassing cold sores

 Does Infrared and red light get rid of cold sores?


They are embarrassing! They are usually painful. They’re contagious. They often pop up at the most inconvenient times! Cold sores are something that more 30-40% of people experience [1]. Some sources even say that around 90% of people will experience a cold sore at least once in their life [2]. This makes it an extremely common problem!


What causes cold sores?

Cold sores are caused by a virus called Herpes Simplex Virus type 1 – HSV-1 [3]. People catch this virus and spread it to others by kissing or other skin-to-skin contact as well as sharing eating utensils, drink bottles or towels [3]. Unlike other viruses like the flu, measles and rubella, once a person becomes infected with HSV-1, the virus will always stay in the body. The way it does this is to hide in the nerves near the location where it initially entered the body [3]. In most cases, this is around the mouth. The initial infection often doesn't result in symptoms so the person doesn't know they caught it. Some people do experience symptoms with the initial infection, including the sores but it may be more like cold and flu symptoms instead. It can happily sit there, sometimes for years, while the person isn't aware it is there. It is only when the body's immune system is weakened by stress, illness or when exposed to UV light, wind or cold that it will reactivate and make its way to the skin surface to cause a sore [3].

Another type of Herpes Simplex virus exists called HSV-2. This virus is the one that is usually attributed to the sexually transmitted infection called herpes. This infection usually presents in the genital area. The virus does have the ability to cross-infect so that HSV-2 can affect the face and HSV-1 can affect the genitals but this is less common. Genital herpes infection has similar cycles of recurrence but it may also not show any symptoms at all. Unfortunately, it is still infectious when there are no symptoms so may be transmitted to sexual partners [9]. The infection can appear like an ingrown hair, a pimple or the typical blistered sore [9]. The use of condoms can help reduce the risk of infection but where there is skin-to-skin contact there is going to be a risk involved.


What are the symptoms of HSV-1?

* Tingling of the lips – this is often how people know a cold sore is coming [3]

* Small blisters on the lips or mouth which enlarge, burst then crust over [3]

* Itching, dryness and irritation around the mouth [3]

* Pain at the location [3]

A cold sore usually lasts no longer than 1-3 weeks [3]. Cold sores can not be cured but steps can be taken to reduce the severity and speed up the healing time. Some people have success with topical antiviral ointments, anti-inflammatory agents or numbing cream to help the symptoms [3]. In extreme cases, some people can be prescribed oral ant-viral medication but they are most effective a few days before the blister shows itself [3]. Cold sores that take longer to heal than three weeks or get worse over time need medical attention to assess whether there are any underlying health problems.

How to prevent cold sores?

People who haven't been infected with the virus can help prevent becoming infected by avoiding skin contact or sharing items with someone who has an active infection.

For those who are infected it is possible to prevent or reduce the number of recurrences by determining what triggers the outbreaks for that person. For instance, for those who experience a cold sore from sun exposure, they should avoid excess sun exposure or consider sun protection such as hats and sunscreen. As mentioned, tingling on the lips or around the mouth can be a sign that a new cold sore is happening. As soon as this sensation is experienced, the chosen cold sore treatment should begin to help potentially prevent it from starting or at least reduce the severity [3].

Can infrared and red lights be used to prevent and treat cold sores?

Yes! There are multiple studies to show that infrared and red light technology is beneficial for cold sores.

Prevention of recurrence

In people who experience frequent cold sore eruptions, red light treatment can reduce the recurrence dramatically! In one study this therapy was found to reduce the average recurrence interval to over 37 weeks from an average of 3 weeks [4]. Some people in this study were able to go a whole year without a new cold sore [4]! They achieved these results with only 10 treatments. This benefit also lasts longer term and doesn't wear off with this reduced recurrence continuing for the five years that participants were followed for [5].

Faster healing time

Studies show that there is an obvious effect on the healing time of cold sores when treated with red light technology [5]. People in the studies experienced great satisfaction because they did not have to endure unsightly facial lesions for as long as they would have without the red light treatment [7]. The average reduction in healing time was  48-72 hours when compared to placebo [7]. Similar results occur with infrared light also with an average time to healing for the active group being 5.3 days, compared with 7.3 for the control group, although there is no change in the amount of time it takes for the cold sore to have a crust form [8].

Reduced pain

Studies show that people experience less pain from their cold sores by using red light on them. These people experienced a reduction of their pain levels by 33% [6]. These people report feeling much more comfortable by using the red lights on their cold sores. As well as pain, some people also experience a burning sensation. This is also reduced with this treatment [7].

For people experiencing genital herpes, using infrared light on lesions for three weeks led to an 82% improvement in pain levels along with a 56-66% improved immune response [10].

Is it safe to use infrared and red lights with cold sores?

When there is a recurrence of cold sores, an infrared and red light device could be used on the area of concern three minutes three times daily for two days or until the symptoms have resolved [7]. Use of infrared and red light technology used in this way is a safe and noninvasive treatment [4]. It has been found to be an effective treatment modality without any observed side effects [5] or pain [6].

How do infrared and red lights compare to the usual topical treatments for cold sores?

Many of the above studies were completed with the standard topical treatments as the control. This means that many of these results aren't being compared to just doing nothing at all. They are actually showing these improved results when compared to using topical treatments.

Red/infrared light is definitely effective but something that some people are concerned about is the financial investment to purchase it. These devices are reusable and, other than new batteries occasionally, require no further cost to maintain. When compared to wasting money on tube after tube of topical treatments which may not work as well, this is an investment that makes sense [3]. This is especially true and even more cost effective for those who have frequent breakouts. In the long run, it is probably going to be much more cost effective. Infrared and redlight can also be used for many other conditions which means it is so much more multi-purpose than the standard topicals which can only be used for cold sores. This treatment can reduce much pain and embarrassment over a person's lifetime – and that is priceless!

Throughout the studies, many people noted that they liked this treatment because it was easy to use and didn't experience any negative effects of the light therapy [7].

For those who are sick of the pain and embarrassment of cold sores or genital herpes, maybe it is time to give infrared and red light technology a try!


[1] Cleveland Clinic, Cold Sores, December, 2019,

[2]  Minesh Khatri, Cold Sores, WebMD, December, 2019,

[3] Johns Hopkins Medicine, Cold Sores, Health department, 2021,

[4] Andreas Schindl, Reinhard Neumann, Low-Intensity Laser Therapy is an Effective Treatment for Recurrent Herpes Simplex Infection Results from a Randomized Double-Blind Placebo-Controlled Study, Journal of Investigative Dermatology, August, 1999,

[5] Muñoz Sanchez PJ, Capote Femenías JL, Díaz Tejeda A, Tunér J, The effect of 670-nm low laser therapy on herpes simplex type 1, Journal of Photomedical Lasers in Surgery, January, 2013,

[6] Ellis Neiburger, The Effect of Low-Level Red Laser Light on the Healing of Oral Ulcers, Glidewell, Chairside Magazine, August, 2009,

[7] Anna Cauthen, Does low-level light therapy accelerate healing time of oral herpes simplex lesions?, Philadelphia College of Osteopathic Medicine, PCOM Physician Assistant Studies Student Scholarship, 2018,

[8] Dougal G, Lee SY, Evaluation of the efficacy of low-level light therapy using 1072 nm infrared light for the treatment of herpes simplex labialis, Journal of Clinical and Experimental Dermatology, October, 2013,

[9] Centres for Disease Control and Prevention, Genital Herpes – CDC fact sheet, US department of Health and Human Services, August, 2017,

[10] Intsar Salim Waked, Abdel Hamid N. Deghidi, Randa Shalaan, Honey phonophoresis versus low intensity laser therapy in female genital herpes, International Journal of Current Research and Review, May, 2014,