Free Prescription Skincare Consultation. Start Now

What's the Best Cold Sore Medicine?

Dr. Patrick Carroll, MD

Medically reviewed by Patrick Carroll, MD

Written by Our Editorial Team

Last updated 3/28/2019

Got a cold sore? Dealing with a cold sore outbreak is never a fun experience, from the pain and discomfort of the sore itself to the effects it can have on your social life.

Because cold sores are so common (about two thirds of people aged under 50 have the HSV-1 virus that causes them, according to the World Health Organization [WHO]), there are numerous medications on the market for getting rid of cold sores.

It’s important to know that there’s currently no cure for HSV-1 or HSV-2, the viruses that cause cold sores and other forms of herpes lesions. Instead, all of the medications available today act by treating the symptoms — namely, cold sores and other types of herpes sores.

Below, we’ve listed and compared all of the cold sore medicines that are available today, from over-the-counter options to prescription options that you’ll discuss with your doctor.

Whether you’re in the middle of a cold sore outbreak and need relief, or if you’ve just started to notice the early signs of a cold sore appearing, the medicines listed below can all help you take control of your cold sore outbreak and benefit from a faster, easier healing process.

Over-the-Counter Medicines for Cold Sores

Cold sore medications fall into two categories. The first are over-the-counter medications, most of which you can freely purchase from your local pharmacy. The second are prescription drugs, which you can only buy with the permission of your doctor.

The most effective cold sore medications are antiviral, meaning they can directly target the virus (HSV-1, or herpes simplex virus 1) that causes cold sores to develop during an outbreak.

There are also over-the-counter cold sore pain relief products available, although these aren’t designed to specifically treat the herpes virus. We’ve covered all of these options in our list of over-the-counter cold sore medications below.


If you’re experiencing a cold sore outbreak and don’t want to use prescription antiviral medicine, you can look for products containing docosanol in your local pharmacy.

Docosanol is a fatty alcohol  with antiviral properties. Sold as a cream, docosanol works by fighting the HSV-1 virus locally, helping to shorten the time required for your lips to heal from a cold sore outbreak.

A 2001 study found that docosanol speeds up cold sore healing by approximately 18 hours on average. While it may be  quite as powerful as the oral antiviral drugs available on prescription, scientific studies show that docosanol works well for healing cold sores.  

In the United States, you can buy docosanol as Abreva®

We’ve covered docosanol in more detail in our guide to cold sore lip balms. While it isn’t quite as powerful as oral antiviral medications such as valacyclovir, docosanol is a good over-the-counter alternative if you’re experiencing a mild to moderate cold sore outbreak. 

Analgesic Lip Balms

Analgesic lip balms are designed to provide relief from cold sores by numbing the lips. These lip balms usually contain natural analgesic ingredients, such as menthol and camphor. Some of the most common analgesic lip balm brands are Carmex® and Herpecin®.

Because these lip balms don’t contain any antiviral ingredients, they won’t actually speed up the healing of a cold sore outbreak. However, the analgesic ingredients can numb your lips, making it easier to deal with the pain, itchiness and discomfort that can accompany a cold sore.

Many of these lip balms also contain moisturizing and SPF protection ingredients, making them good to keep around if your lips are sensitive to sunlight or dry weather.

rx cold sore treatment, right to your door

Cold sores only take 24 hours to get rid of. Connect with a healthcare provider to understand your fever blister treatment options.

Prescription Medicines for Cold Sores

If you get recurring cold sore outbreaks, or you’re going through a particularly serious cold sore outbreak, it’s generally best to talk to your doctor about switching from an over-the-counter cold sore treatment to a prescription antiviral medicine.

Oral antiviral drugs work by inhibiting the HSV-1 virus replicating within the body. Once you start taking the medication, the virus is blocked from spreading within your cells. This speeds up recovery and makes it easier for your immune system to fight back against the virus.

There are three prescription antiviral medications used to treat herpes, all of which work using a similar mechanism of action. These drugs are valacyclovir, acyclovir and famciclovir.


Acyclovir was one of the first oral antiviral drugs to come onto the market. It was developed in the 1970s and is today one of the most widely used prescription drugs for treating cold sores and genital herpes (both caused by HSV).

Taken orally, acyclovir is absorbed by your body and starts inhibiting the HSV-1 or HSV-2 virus from reproducing within your body. It works quickly and effectively, giving you faster healing in the event of a cold sore outbreak.

Despite these advantages, acyclovir does have some downsides. One of the  biggest of these is that it isn’t very bioavailable when compared to other drugs associated with it, like valacyclovir, meaning a smaller amount of the drug makes its way through the liver and into your system.

This means that you might need to take a slightly higher amount of acyclovir, compared to other medications such as valacyclovir, for similar results.


Valacyclovir is a popular antiviral drug that’s used to treat cold sores and genital herpes. In the United States, it’s usually sold as Valtrex, which was the original  valacyclovir-based drug to come onto the market.

These days, valacyclovir is available as a generic medication, meaning there’s no need to ask for a specific brand name when you purchase it.

Valacyclovir is a prodrug, meaning it converts to another drug (acyclovir) once it's absorbed by your body. The bioavailability of valacyclovir is higher than acyclovir,with one study demonstrating that  a 500 mg dose had similar effects to a two 400mg  doses of acyclovir.

For this reason, Valacyclovir is one of the most widely prescribed oral antiviral drugs, particularly for cold sores and other herpes-related issues. You can read more about valacyclovir in our 101 guide, which covers everything from typical dosages to side effects, brand names and more.


Famciclovir is another oral antiviral medication that targets the herpes virus. Unlike acyclovir and valacyclovir, which are usually used to treat HSV-1 (cold sores) and HSV-2 (cold sores or genital herpes), famciclovir is usually prescribed to treat other herpes viruses.

Despite this, famciclovir can and occasionally is used to treat cold sore outbreaks. However, the majority of doctors will opt for widely used antiviral drugs such as valacyclovir or acyclovir before prescribing famciclovir for a cold sore outbreak.

Which Cold Sore Medicine is Best?

All cold sore medications have specific advantages and disadvantages, ranging from their cost or convenience factor to their effectiveness in treating the symptoms of an HSV-1 outbreak.

As a result, there’s no “best” cold sore medicine. If you're experiencing a cold sore outbreak and want relief, the best approach is to discuss your situation with your doctor and follow their advice regarding drugs and other treatments.

If you’re interested in reading more about how different oral antiviral drugs work, you might find our guide to valacyclovir vs. acyclovir vs. famciclovir interesting. It compares the three antiviral drugs using a variety of factors, from oral bioavailability to their effectiveness in studies.

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. Learn more about our editorial standards here.