The 2 types of herpes: HSV-1 & HSV-2

HSV-1 and HSV-2: Same virus family, different preferences

HSV-1 and HSV-2 are two strains of the herpes simplex virus. They’re closely related (genetically about 50% identical) and they cause very similar symptoms. The main difference? Where they prefer to live:

• HSV-1 prefers the oral area. This is the virus behind cold sores (also called fever blisters). About 48% of Americans ages 14–49 have HSV-1, and globally an estimated 3.8 billion people carry it. Most people get it as children through non-sexual contact like a kiss from a relative.
• HSV-2 prefers the genital area. About 12% of Americans ages 14–49 have HSV-2. It’s primarily transmitted through sexual contact.

But here’s the thing: either type can infect either location. HSV-1 can show up on the genitals (usually through oral sex), and HSV-2 can occasionally appear on the mouth (though this is rare). The virus is the same family, just two strains with different neighborhood preferences.

HSV-1 vs. HSV-2: Side-by-side comparison

How common is each type, really?

Herpes is one of the most common infections on the planet. Here’s how common:

• HSV-1: About 3.8 billion people worldwide have it, that’s roughly half of the global population under age 50. In the U.S., about 48% of people ages 14–49 test positive for HSV-1 antibodies. Most people got it in childhood from a kiss or shared cup, no sexual contact needed.
• HSV-2: About 491 million people worldwide ages 15–49 have it. In the U.S., about 12% (roughly 1 in 6) of people ages 14–49 have it. It’s primarily sexually transmitted.

Together, these numbers mean that the majority of adults carry some form of the herpes virus. And about 80% of people with herpes don’t even know they have it, because they’ve never had a noticeable outbreak or been tested for it.

When you put it that way, herpes isn’t the rare, scary thing stigma makes it out to be. It’s one of the most common human infections in existence.

The names can be confusing, here’s a quick reference

Herpes terminology is a mess. You’ll see HSV-1 and HSV-2 referred to in different ways depending on the source. Here’s a decoder:

HSV-1 is also called:

• Cold sores / fever blisters
• Oral herpes / mouth herpes
• Herpes simplex virus type 1
• Herpes type 1

HSV-2 is also called:

• Genital herpes
• Herpes simplex virus type 2
• Herpes type 2

Important: “oral herpes” and “genital herpes” describe the location of the virus, not the type. You can have genital HSV-1 (from oral sex) or oral HSV-2 (rare, but it happens). The type of virus and the location it lives in are two separate things.

HSV-1 as a cause of genital herpes

This is one of the most important things to understand: over half of all new genital herpes diagnoses are now caused by HSV-1, not HSV-2. The most common way this happens is through receiving oral sex from someone who has oral HSV-1 (cold sores), even if they don’t have a visible sore at the time.

That means someone who has “just cold sores” can give their partner genital herpes through oral sex. It’s the same virus, just in a different location. For a deeper dive on this topic, read our full article on genital HSV-1 and oral sex.

The silver lining: genital HSV-1 tends to be milder than genital HSV-2. It recurs less often, sheds less frequently, and is less likely to be transmitted to a partner from the genital area. Many people with genital HSV-1 have one initial outbreak and then rarely (or never) have another.

How often does each type shed? (Viral shedding rates)

Herpes can be passed to a partner even when no visible symptoms are present. This is called asymptomatic shedding, the virus traveling to the skin’s surface without causing any sores or symptoms.

How often this happens depends on both the virus type and where it lives:

• Genital HSV-2: sheds on approximately 10–15% of days (the most frequent)
• Oral HSV-1: sheds on approximately 9–25% of days (varies by individual; people with frequent cold sores shed more)
• Genital HSV-1: sheds on approximately 3–5% of days (and decreases over time, after 2 years of infection, shedding drops to about 4 days per year)
• Oral HSV-2: sheds on approximately 1% of days (very rare)

This matters because shedding frequency directly affects transmission risk. Less shedding = lower chance of passing the virus. This is one reason genital HSV-1 is considered less transmissible than genital HSV-2.

How outbreaks differ between HSV-1 and HSV-2

Both types can cause outbreaks, clusters of small blisters or sores that eventually break open and heal. But how often outbreaks happen and how severe they are depends on the type and location:

Genital HSV-2 (the most common cause of recurrent genital herpes):

• Average of 4–6 outbreaks in the first year
• Outbreaks become less frequent over time (many people go from several per year to one or none)
• Outbreaks are typically shorter and milder than the first episode

Genital HSV-1 (acquired via oral sex):

• The first outbreak can be just as intense as HSV-2
• But recurrences are much less common, typically 0–1 per year after the first year
• Many people never have a noticeable recurrence

Oral HSV-1 (cold sores):

• Varies widely, some people get cold sores several times a year, others go years between outbreaks
• Triggers often include sun exposure, stress, illness, or fatigue

For both types, learning to recognize your prodrome symptoms (the tingling, burning, or itching that often comes before an outbreak) helps you respond quickly with medication and avoid contact during the most contagious period.

Testing: How to know which type you have

Knowing your herpes type matters because it affects your outlook, how often you might have outbreaks, how likely transmission is, and what to tell a partner. Here’s how testing works:

If you have active sores:

• A swab test (PCR or viral culture) of the sore can identify whether it’s HSV-1 or HSV-2. This is the most reliable method when sores are present. Get tested as soon as possible, the sooner the sore is swabbed, the more accurate the result.

If you don’t have sores:

• A type-specific IgG blood test can detect antibodies to HSV-1 and HSV-2 separately. This test works best at least 12 weeks after potential exposure, since it takes time for antibodies to develop.
• The IgM test is less reliable and not recommended, it can’t distinguish between types and often produces false positives.

If your doctor only tells you “you have herpes” without specifying the type, ask for a type-specific test. The distinction between HSV-1 and HSV-2 has real practical implications for managing your health and having informed conversations with partners.

Can you have both HSV-1 and HSV-2?

Yes, it’s possible to carry both types, though it’s not as common. Having HSV-1 first does provide some partial cross-protection: the antibodies your body has built against HSV-1 can reduce the severity of a first HSV-2 outbreak and may lower (but not eliminate) the chance of acquiring HSV-2.

One important note: HSV-1 does not turn into HSV-2. They are permanently distinct strains. If someone with oral HSV-1 gives their partner genital herpes through oral sex, that partner has genital HSV-1, not HSV-2. The type never changes based on location.

Treatment: Same medication for both types

Here’s the straightforward part: HSV-1 and HSV-2 are treated with the exact same antiviral medications:

• Valacyclovir (Valtrex), most commonly prescribed; taken orally
• Acyclovir, the original antiviral; available orally and topically
• Famciclovir, another oral option

These medications can be used in two ways:

1. Episodic therapy: Taking medication at the first sign of an outbreak to shorten its duration and severity
2. Suppressive therapy: Taking medication daily to reduce outbreak frequency, lower asymptomatic shedding, and decrease transmission risk by about 48%

Your doctor can help you decide which approach makes sense based on how often you get outbreaks, whether you’re in a relationship, and your personal preference.

The stigma double standard

Let’s address the elephant in the room. If nearly half of Americans have HSV-1 and nobody bats an eye (“Oh, it’s just a cold sore”), then why does HSV-2 carry so much shame? The viruses are closely related, cause similar symptoms, and are treated with the same medications.

The stigma around genital herpes is not a medical phenomenon, it’s a cultural one. It’s rooted in the shame our society attaches to anything associated with sex. The same virus that’s casually mentioned when it shows up on someone’s lip becomes a source of deep shame when it shows up below the belt. That tells you everything you need to know about where the stigma really comes from.

The truth is: who you are is far more important than what virus you carry. Herpes (whether it’s type 1 or type 2, oral or genital) is a common, manageable skin condition. It doesn’t define your worth, your attractiveness, or your future.

The bottom line

HSV-1 and HSV-2 are two strains of the same virus. The differences between them are mostly about location preference, recurrence frequency, and shedding rates, not severity or seriousness. Both are incredibly common, both are treatable, and neither one says anything about who you are as a person.

If you’ve been diagnosed with either type, you’re far from alone. Armed with the right information, you can manage this confidently and keep living a full, connected life. The virus is a small part of the picture. Who you are is the big part. :)

For more, download our free e-book and handouts, they include a printable summary of shedding rates, transmission data, and tips for having the conversation with a partner.