Containing several powerful active ingredients, Listerine has become a popular cold sore treatment. Alternative treatments are usually a slippery slope, and this potent mouthwash also has several side effects, not limited to infection and chemical burn.

Although cold sores never hang around too long, typically 8 to 14 days, their very presence can stop some people in their tracks. This is especially true if you want to avoid being embarrassed at work and various social occasions. Cold sore cover-ups can make life more tolerable.

We will look closely at the pros and cons of Listerine and why alternative remedies are so popular. We will also advise you on some OTC cold sore medicines to make your experience less of an inconvenience.

Is Listerine worth trying? Let’s take a closer look.

Is Listerine an Alternative Cold Sore Treatment?

Listerine is popular because it is potent.[1] The same antiseptic mouthwash that can zap germs and cause your eyes to water within seconds is worth a look to some. Especially those who actively seek out alternatives to OTC methods.

Does it work? As briefly noted, Listerine does contain some of the right ingredients to heal cold sores.[2] The same formula that works wonders inside your mouth can remedy fever blisters. Because people are constantly searching for new ways to dry out their cold sores, Listerine fits the “trendy” qualification.

Listerine, like many harsh alternative methods, essentially turns cold sores into a dried up skin blemish. The application of hydrogen peroxide to cold sores also produces a similar result. The once fresh and fluid-filled blister is reduced to something that looks like dried clay. Quite a harsh visual, but both Listerine and hydrogen peroxide are harsh treatments.

Courtesy of its chemical potency and easy accessibility, Listerine caters to those who are looking for a quick fix.

To summarize:

  • Listerine is a powerful germ killer. There is a school of thought that Listerine can dispatch cold sores in the same way that antiseptic dispatches oral germs. Most of these conclusions come from message board posters who have used Listerine as a cold sore treatment.
  • Listerine dries out cold sores. It can provide HSV-1 sufferers a “quick fix” if they are in need of faster healing.
  • In respect to active ingredients, Listerine contains eucalyptol, menthol, methyl salicylate, and as it relates inactive ingredients, Listerine is comprised of roughly 27% alcohol.

What are the Side Effects of Listerine?

Listerine can be a double-edged sword when it comes to treating cold sores. The same potency that has garnered so much attention can also be a negative. A mouthwash of this nature is potent. This potency can introduce some new problems.

While dabbing a small amount of Listerine onto a cotton ball can be safe, lack of direction can be costly. Applying antiseptic to an open wound (the ulcer stage) is just like pouring salt into a giant cut. This is especially true when the antiseptic in question is not designed for skin healing. Outside of the intense pain that you’ll experience, a potential infection can also arise.

Although the active ingredients in Listerine can dry out a cold sore, it can also dry out the entire area. This includes surrounding skin as well as potentially new and tender skin beneath the sore.

One of the main side effects of Listerine is the potential for chemical burn. While your cold sore will likely be healed, a new and more serious issue will be introduced. Immediate medical treatment will be required. Some form of antibiotic will likely need to be prescribed by your physician.

For the reasons noted above it is our recommendation that Listerine should NOT be used to treat cold sores. Although the ingredients are in place for potential effectiveness, the absence of systematic toxicological studies means that an accurate safety assessment cannot be made.[3]

To recap:

  • The same potency that can heal a cold sore outbreak can also damage your skin. This is certainly not a wise trade by any means.
  • Applying Listerine to a cold sore, especially during the ulcer stage, can be quite harmful and painful.
  • Listerine can cause a chemical burn at the application site. This can introduce issues that will need to be treated by a doctor.

Why are Alternative Remedies so Popular?

Alternative cold sore treatments are popular due to their promise of quick healing.

Many people who search for alternatives not only want a quick fix, they want to save money. Why go to the pharmacy when you can use household supplies? There is a certain level of seduction in that type of thinking.

While some alternatives do work and are safe, most are problematic at best. Entertaining methods that are neither safe nor provide relief is the bottom floor. Unfortunately, some cold sore sufferers find themselves in more trouble than they bargained for when all is said and done.

If you are considering using an alternative, it is critical that you do your research. Selections such as essentials oils for cold sores, for example, are mostly safe and effective. Real results have been found using natural products.

Will Listerine Cure Cold Sores

To summarize:

  • Alternative remedies are trendy. While some can provide relief, most are gimmicks and some are dangerous. Finding new ways to remove a blister is a fad. We advise you to be wise and perform your own research. Two message board posts singing the praises of a DIY remedy should never be viewed as a ringing endorsement for success.
  • Cold sore removal should never be your main objective. Your health and general safety should always come first. Replacing your cold sore with a chemical burn simply because you wanted a quick fix is not wise.

How Can You Heal Cold Sores Fast?

The safest and most effective way to heal cold sores fast is a proven OTC medication or a prescription medicine from your doctor. From creams, gels, ointments, and patches, the OTC market is quite expansive.

On average, a cold sore outbreak will last 8-14 days. This period is defined by the initial tingle symptom through the healing stage. By taking advantage of an OTC medication the life of a cold sore can be cut in half. In some cases, cold sores will only last 2-3 days.

While cold sores can be annoying, embarrassing, and painful, the most logical course of action will always be the best. There are FDA-approved treatments that can provide fast healing. We encourage you to lean on products designed to do the job rather than problematic fads.

Listed below are just two of the most common OTC treatments that can heal cold sores fast:

Real Treatments are Better than Experiments

The final takeaway from this guide is to simply select what works, both in terms of safety and healing. While we do not recommend Listerine as an active cold sore healer, this is not to say that all alternative methods are bad.

We advise you to avoid gimmicks and fads. OTC treatments exist because they work and the majority of HSV-1 sufferers stand by those remedies. If mouthwash proved to be the great cure-all, then Abreva would likely be out of business. This hasn’t happened for a reason.

Never underestimate the power of your own decision making when it comes to treating and healing fever blisters. How you address the issue can be the difference between fast healing or prolonged infection and scarring.


  1. Alshehri FA. The use of mouthwash containing essential oils (LISTERINE®) to improve oral health: A systematic review. The Saudi Dental Journal. 2018;30(1):2-6. doi:10.1016/j.sdentj.2017.12.004.
  2. Meiller T.F., Silva A., Ferreira S.M., Jabra-Rizk M.A., Kelley J.I., DePaola L.G. Efficacy of Listerine® Antiseptic in reducing viral contamination of saliva. J. Clin. Periodontol. 2005;32(4):341–346.
  3. Vlachojannis C, Al-Ahmad A, Hellwig E, Chrubasik S. Listerine® products: an update on the efficacy and safety. Phytother Res. 2016;30:367–373. doi: 10.1002/ptr.5555.