Can Oral Herpes Be Spread to Genitals?

A cold sore on the lower lip on the second day after onset. Image: CDC

Herpes simplex virus is mystifying, fascinating, and sneaky. Mystifying because we have yet to unravel all of its secrets; fascinating because when we do uncover one of its mysteries, we are amazed by the capabilities of such a tiny, microscopic object; and sneaky because it enters our bodies by stealth and conceals itself in our cells, taking us by surprise when it comes out of hiding and causes outbreaks of blisters and other lesions.

It can also be confusing. Herpes simplex virus actually comes in two flavors: HSV-1 and HSV-2. HSV-1 is associated more with oral herpes, which can cause “cold sores,” a type of blister that appears on the lips or face. HSV-2 is associated more with genital herpes, which can cause blisters and other lesions in the genital area. It used to be standard to describe HSV-1 as an “above-the-waist” infection and HSV-2 as a “below-the-belt” infection — but now many researchers are pointing out that it’s more appropriate to say that HSV-1 is both an orally and genitally transmitted infection while HSV-2 is a predominantly genitally transmitted infection. If HSV-1 enters the body in the genital area, it can cause a genital herpes infection — and likewise, if HSV-2 enters the body in the facial area, it can cause an oral herpes infection.


Using condoms and dental dams during oral sex reduces risk of herpes transmission.


What exactly is a cold sore, anyway? A cold sore, also known as a fever blister, is a cluster of blisters that can pop up around the lips or even in the mouth. Sometimes, cold sores are so painful that eating or drinking is difficult, and in extreme cases sufferers must be treated for dehydration. An especially severe infection could also cause high fever or swollen lymph nodes, and in young adults a first oral HSV-1 infection might be misdiagnosed as tonsillitis, possibly leading to unnecessary tonsillectomies. Most symptomatic first-time cold-sore outbreaks occur during childhood, and take about two or three weeks to clear up. Luckily, the first infection is almost always the most severe, and when the infection is reactivated it usually happens without symptoms.

Because both cold sores and genital herpes are caused by herpes simplex viruses, and because oral herpes is so common, many people are concerned that they might be more vulnerable to acquiring a genital herpes infection than they previously thought. They might have a lot of questions, and if they’ve sought answers to those questions, they might have heard a lot of conflicting answers. Let’s see what the scientific literature has to say.

  • Can I get genital herpes if someone with cold sores performs oral sex on me?

Because HSV-1, the virus responsible for most oral herpes infections, can also cause genital herpes, many people wonder if someone with cold sores can transmit the virus to someone else by performing oral sex, resulting in a genital herpes infection. Other people wonder if HSV-1 can be transmitted via oral contact with the anus, resulting in a herpes infection in the rectal area. The answer to these questions is: Yes!

While HSV-1 only accounts for around 30 percent of genital herpes infections overall, many research teams are finding that HSV-1 is the predominant cause of genital herpes in some countries (such as Sweden) and in some U.S. populations, especially of younger females. For example, among students at a large Midwestern public university, researchers found that HSV-1 caused 31 percent of genital herpes cases in 1993 and grew to 78 percent in 2001. The increase was even more pronounced in females. This trend, in which HSV-1 infections in the genitals predominate over HSV-2, seems to be most common among younger people, women, and men who have sex with men. This change might be due to the fact that condom use for vaginal and anal intercourse is considered normal in most populations — while most people don’t use condoms or dental dams during oral sex, leaving them vulnerable to acquiring HSV-1 (and other infections!) from a partner.

This might sound like terrible news, since most of us are infected with HSV-1 and we might enjoy oral sex. But there is some good news. First of all, HSV-1 likes to live in the trigeminal ganglion — in the face. Because HSV-1 feels more at home in the trigeminal ganglion, an infection in that location is more likely to reactivate and cause cold sores periodically throughout a person’s life. When HSV-1 finds itself living in the sacral ganglion in the genital area, it doesn’t reactivate very often. So, if you are infected with HSV-1 in your genital area after receiving oral sex, recurrences will be uncommon and your infection will be milder than if you were infected with HSV-2, which is a related virus that is more strongly associated with genital herpes.

  • Can I be infected with HSV-2 in my facial area if I perform oral sex on someone with an HSV-2 infection in their genitals?

Just as HSV-1 can pass from the mouth to the genitals to cause a genital herpes infection, so too can HSV-2 pass from the genitals to the mouth to cause an oral herpes infection. However, oral HSV-2 infections aren’t as common as genital HSV-1 infections. Although there are some documented cases of oral HSV-2 infections, they aren’t very widespread. Furthermore, just as a genital HSV-1 infection is milder and less prone to recurrences than an HSV-2 infection in that area, so too is an oral HSV-2 infection milder and less prone to future outbreaks.

  • Can the virus be transmitted if someone isn’t showing any symptoms?

Unfortunately, just because someone lacks a telltale cold sore doesn’t mean they’re not infectious. It is quite possible for the virus to reactivate, not cause symptoms, but still “shed” from a carrier, at which point it can be transmitted to someone else — via skin-to-skin contact, saliva, or even tears. One large study, using a sensitive DNA amplifying technique called PCR, detected the asymptomatic shedding of HSV-1 on 33.3 percent of days. Another study of 50 people found that 90 percent of them had HSV-1 in their saliva at least once during a 30-day period.

Shedding patterns can be further influenced by what triggered the virus to reactivate — for example, higher-than-average amounts of virus are found in saliva samples from patients with oro-facial fractures.

  • If I’ve already been exposed to HSV-1 in my facial region, am I immune to reinfection in my genitals?

Some people think that already being orally infected with the cold sore virus makes them immune to HSV-1 infections in their genitals. It’s true that if you have an oral HSV-1 infection, you might have some degree of protection against acquiring HSV-1 infection in your genitals — but we don’t know to what degree a previous HSV-1 infection protects us from subsequent infections elsewhere in our bodies. More study is needed to answer this question more fully, but the short answer is that yes, reinfection in the genitals is possible.

  • Does a previous HSV-1 infection protect me from a subsequent HSV-2 infection?

As mentioned previously, most of us are orally infected with HSV-1 as children. Unfortunately, a preexisting HSV-1 infection doesn’t protect us from acquiring an HSV-2 infection later in life, though it’s possible that it will help mitigate symptoms of a first HSV-2 outbreak. Those who already have an HSV-1 infection are much less likely to experience symptoms upon an initial HSV-2 infection. Likewise, a previous HSV-2 infection does not protect someone from acquiring an HSV-1 infection. It’s possible for HSV-1 and HSV-2 to infect the genitals at the same time — it just might not be as likely.

  • Can my genital HSV-1 infection be transmitted to my partner’s genitals?

When HSV-1 infects the genitals, it usually got there as a result of oral sex. Because genital HSV-1 infections have fewer recurrences and are associated with less asymptomatic shedding, the genital-to-genital spread of HSV-1 is not as common.


If you want to find out if you’ve been infected with HSV-1 or HSV-2, you can get a blood test at a Planned Parenthood health center. This test will only tell you if you’ve been infected with either of these viruses, but in the absence of symptoms it won’t tell you where in your body the infections are located. We can also answer any questions you have about herpes and discuss antiviral medications with you.

20 thoughts on “Can Oral Herpes Be Spread to Genitals?

  1. Pingback: STD Awareness: “Can I Get an STD from Oral Sex?” | Planned Parenthood Advocates of Arizona | Blog

  2. Pingback: STD Awareness: Asymptomatic Shedding of Herpes | Planned Parenthood Advocates of Arizona | Blog

  3. Pingback: STD Awareness: How Can I Protect Myself if My Partner Has Herpes? | Planned Parenthood Advocates of Arizona | Blog

    • If you only have HSV-1 in your genitals, you will not pass the virus through your mouth, through saliva or kissing. However, most people are orally infected with HSV-1, even though most people do not have symptoms.

  4. I’ve had HSV1 since I was a child and have regular out breaks. I’ve never had any noticeable genital symptoms and usually practice safe sex.. I recently started a new relationship and after an outbreak of cold sores had healed I gave oral sex to my b/f. He’s never symptoms of either HSV1 or 2. I then had stinging burning, back pain and swollen lymph nodes in my groin. I’ve been tested negative for all other STI’s, is it possible I passed my HSV1 to my B/f genitals which he then passed back to mine? I get the idea this isn’t possible and he’s never had symptoms himself. I can’t find another cause for these symptoms at present and there’s to point to me having a blood test as I have oral herpes. I would just like some clearer guidance. Please help, thank you

    • Hi Maisie! It is possible to pass HSV-1 from your mouth to your partner’s genitals, and then for HSV-1 to be transmitted from your partner’s genitals to yours. If symptoms are present, the sores can be sampled and analyzed in a lab to confirm if they are caused by HSV-1. (A test for the presence of virus in the sores would be different from a blood test.) Luckily, genital infections with HSV-1 tend to be more mild, and recur less frequently.

  5. I recently had genital sores and was tested for hsv-1 and 2 recently by both PCR and antibody tests because I have been in my current relationship 10+ years and believed that we’ve both been faithful ( or at least I knew I had been). My PCR test was positive for HSV-1 and the antibody test negative for both indicating a recent exposure. My partner has never had any genital sores but has had cold sores and we do practice oral sex. Is there any reason we have to worry about ASYMPTOMATIC transmission back to his genitals after I recover from this initial outbreak and is there a reason he would need the blood work as he’d likely test positive anyhow?

    • It was linked in the article, but just in case you didn’t take a look, I’ll link to it again, as I highly recommend this post by Dr. Jen Gunter about herpes blood tests. One of the key points she makes is that “There is no blood test that can tell you immediate exposure/recent infection,” so you might want to look more closely at what kind of tests your doctor ordered.

      To answer your question, yes, HSV-1 can be transmitted from one person’s genitals to another person’s genitals, even when the partner with HSV-1 is asymptomatic. It’s not as common as HSV-2 transmission to the genitals, but it is possible. You can read more about asymptomatic transmission here.

      If he already has HSV-1 (which the cold sores would indicate), a blood test would come up positive for the virus, but it wouldn’t tell you where in the body the virus was lurking. However, if he got symptoms in his genitals, he could have the infection confirmed with a lab test. Luckily, most people infected with HSV-1 or HSV-2 don’t have symptoms.

  6. I had hsv1 genital infection 2yrs ago from my partner lips during oral sex . This is my third episode though am healthy.is there a way to eradicate the disease?am I concedired recurrent infection?
    Is he gonna have it if we have sex during the prod rom ?should he start on prophylaxis acyclovir?
    Thx

    • Hi Linda! There is no way to eradicate a herpes infection, but you can lower the risk of recurrence through medications like acyclovir, and through a healthy lifestyle (avoiding stress, quitting smoking, and getting plenty of sleep).

      I have not heard of people without herpes avoiding it by taking acyclovir — only the partner with herpes takes that medication to reduce viral shedding. If your boyfriend is negative for HSV-1 in his genitals, he could acquire it from you via vaginal intercourse, even if you’re not having symptoms.

      To learn more about reducing your partner’s risk, check out this article.

  7. I just found out that my boyfriend has oral herpes (hsv 1), and that most people have this. If i already have it, and the disease is dormant, is it possible for me to get genital herpes, type 1 or 2?

    • If your boyfriend has HSV-1 in his facial area (which, as you rightly point out, most of us have), then he can transmit it to your genitals via oral sex, even if you are already infected with HSV-1 in your facial area. He can’t transmit HSV-2 if he is not infected with it. I hope that answers your question!

  8. I recently got hsv1 from my girlfriend that had hsv1 on her mouth. We didn’t know until now what could happen and the risks. I now have genital herpes and also around my recrum…both are horrible and excruciating pain. I went to the doctor and found out it was hsv1 and the time frame and symptoms showed that, also her having a cold sore but no vaginally symptoms told us I got it from her. I have two questions….he prescribed me Valacyclovir, is there anything else I can put on the sores to subside them and relive the pain….and since i.have it down there now could I get it again down there and or can I give it to her down there since she already has hsv1?

    • Hi Jason: If you have a genital HSV-1 infection, you unfortunately have it for life. But on the other hand, a genital HSV-1 infection is usually milder than an infection with HSV-2, with fewer (if any) recurring outbreaks. You can learn more about HSV-1 here.

      If your girlfriend has facial HSV-1, she can also be infected with HSV-1 in her genitals. (She might be already — without symptoms, there is no way to tell.) The HSV-1 infection in the facial area might make her more resistant to acquiring an HSV-1 infection in the genital area, but it doesn’t confer total immunity.

      I’m really sorry to hear that you’re in such horrible pain. They say that the first outbreak is the worst, so with time it should subside. Many people never have recurring outbreaks after the first one, so with luck you’ll fall into that camp. In addition to the medication, Planned Parenthood recommends warm baths; cotton clothes to prevent chafing; keeping the sores dry; cool compresses or ice packs; and pain relievers such as aspirin, acetaminophen, or ibuprofen. Good luck!

  9. I just recently received oral from someone that told me they’ve been diagnosed with oral hsv1. How high are the chances that I will get hsv1 in the genitals and how long should I wait to feel symptoms aswell as to get tested?

    • Hi JM: I don’t know if there has been much study on the chances that you would get HSV-1 in your genitals after exposure by oral sex. Most of us are already infected with HSV-1 in our facial areas, which (as this article says) gives you some degree of protection from a genital infection, but we don’t know precisely how much protection it would give you. If you don’t have symptoms, a blood test will only tell you if you have antibodies to HSV-1, but it won’t tell you where in your body the virus resides. Therefore, if you have a facial HSV-1 infection (as most of us do), your test will be positive — but it won’t necessarily mean that you have a genital infection.

      Symptoms don’t always show up, but if they do, it usually takes 1 day to 3 weeks. If you do have symptoms, get them checked out by a medical professional for the most accurate diagnosis. Write down your questions so you don’t have to worry about remembering everything, and your health-care provider can answer them.

      • For the past week, I’ve been worried about my husband. We are married and separated(not legally) and also long distance. The last time him and I have sex with one another was on Jan. 6th. But he was recently tested for herpes since he noticed an itchy “skin irritation” on his groin area. He tested positive for HSV-1. He claims to no have had any type of sex since we’ve been separated, and believes he contracted the virus after someone put their mouth on his finger and he used the restroom without washing his hands prior. Is this possible? I’m confused and apparently so is his doctor.

  10. My girlfriend recently received sperm from someone who just told us that he has Hsv 1 . Can she get it even though we used a syringe ?

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