How to Shrink a Cold Sore: Herpes Expert Explains the Biology Behind the Best Treatments

When it comes to treating cold sores, the typical drugstore is well stocked with creams, balms and ointments all claiming to treat the red, pus-filled and uncomfortable growths. But some of these options may ease some of the discomfort, not all of them are built to tackle the biology of the virus that actually causes cold sores.

Cold sores actually a product of a viral infection, from one of two types of herpes simplex virus. Infections on the face or mouth are usually called by herpes simplex virus one (HSV-1). Sores that appear near the genitals, are generally caused by herpes simplex virus two (HSV-2). Occasionally each of these viruses will stray from its preferred location and infect another part of the body, but when it comes to cold sores on the mouth most of the time HSV-1 is to blame.

But regardless of what virus is behind it, nurse practitioner Terri Warren, RN, who specializes in herpes explains that there’s no true cure for either virus.

That doesn’t mean that someone will always have cold sores, but the viruses that make them appear now and again sticks around for life. It’s also incredibly common, the American Sexual Health Association estimates that that nearly 50 percent of the population has an oral herpes infection, even if they don’t know it yet.

“It stays in your system for a lifetime,” Warren tells Inverse. “It can be given off when you have a sore present or when you don’t have a sore present. I would describe it as potentially contagious at any time. That’s kind of what makes it difficult for people.”

Can You Shrink a Cold Sore?

Warren explains that there are over-the-counter medications — like creams — to help treat, or “shrink” cold sores once they appear, and there are anti-viral medications which wreak havoc with the virus itself. Of the over-the-counter medications there is only one that has been clinically shown to reduce cold sores: Abreva, which has FDA-approval.

There are other topical creams available as well. Still, Warren prefers the oral anti-viral treatments, which some in pill form. There are three primary anti-virals: acyclovir, valacyclovir, famciclovir. All of these require a prescription, but Warren adds that they’re worth the extra effort.

"“I would describe it as potentially contagious at any time. That’s kind of what makes it difficult for people.

“There are some topical medicines available for cold sores. We did the clinical trials for those in our practice and I didn’t think they were very effective,” she says. “I think that the oral medications are far more effective.”

Treatment Strategy:

The anti-viral medications actually look to tackle the virus itself by interrupting the way it survives in human cells. To infect a cell, a virus hijacks the cell and tricks it into replicating the virus itself— allowing it to multiply. An anti-viral medication, interrupts that process, and stops the virus from replicating. If the timing and dosage of the anti-viral is right, Warren explains that it can help derail a cold sore outbreak.

Warren explains that one way to go about things, at least for HSV-1, is not to wait until a full cold sore blossoms. If someone feels a cold sore coming, and seeks treatment, she explains that the treatment is pretty easy. Usually, it’s one dose of an oral antiviral, usually valacyclovir (it goes under the brand name Valtrex) followed by another dose 12 hours later. Together, that can mess with the virus enough to either shorten the length of the outbreak if it does happen or potentially stop it in its tracks.

“If you can stop viral replication with a high enough dose [of anti-viral] than you can frequently stop an outbreak from coming,” she adds.

Of course, these treatments can only control the virus, not banish it completely. The idea that it’s impossible to truly shake a herpes infection is a bit disheartening. But fortunately there’s a good way to manage the symptoms of an outbreak. The best strategy it to plan ahead, and stop a cold sore before it strikes.