Certain sexually transmitted infections (STIs) and diseases (STDs) — including herpes simplex virus and cytomegalovirus — can be transmitted through kissing. Others can be transmitted orally.

Kissing can be one of the most exciting parts of a relationship. But you may also feel wary of kissing if you’re with someone for the first time.

The best way to avoid getting an STD/STI from kissing is to have a direct, transparent conversation about it with your partner. This can be intimidating, but setting boundaries early can help you avoid an infection.

Let’s dive right into the most common STIs that can be spread by kissing. We’ll also talk about those that are less likely to be transmitted by mouth but can still be passed orally.

Herpes simplex virus (HSV) can take two different forms.


Also called oral herpes, HSV-1 can easily be passed on through kissing. It’s also common: 67 percent of people under 50 have the virus in their bodies.

The most notable symptom is a small white or red blister on the mouth or genitals. It may ooze or bleed during an outbreak. Touching or kissing an active cold sore can transmit the virus. The virus can also be spread when no symptoms are present.

HSV-1 may be spread by sharing saliva or items like utensils that have come into contact with the virus, though this is somewhat rare. HSV-1 can also affect the genitals and be spread through oral, genital, or anal sex.


Also called genital herpes, this virus is more commonly spread through sexual contact — oral, genital, or anal — than through kissing. But mouth-to-mouth transmission is still possible. HSV-2 symptoms are basically the same as those of HSV-1.

Neither HSV-1 nor HSV-2 can be fully cured. You likely won’t experience many symptoms or complications unless you have a compromised immune system. For active infections, your doctor may recommend antiviral medications such as acyclovir (Zovirax) or valacyclovir (Valtrex).

Cytomegalovirus (CMV) is a viral infection that can be passed on through contact with saliva that contains the virus. It can also be transmitted through the following fluids that contain CMV:

  • urine
  • blood
  • semen
  • breast milk

It’s considered an STI because it’s often transmitted through oral, anal, and genital sexual contact, too.

Symptoms of CMV include:

CMV isn’t curable but someone with CMV may never have symptoms. Like herpes, CMV can cause symptoms if you have a compromised immune system. Your doctor may recommend similar treatments to HSV.

Syphilis, a bacterial infection, isn’t typically transmitted by kissing. It’s more commonly spread through oral, anal, or genital sex. But syphilis can cause sores in your mouth that can transmit the bacteria to someone else.

Deep or French kissing, which includes touching tongues together, can also increase the risk of infection. That’s because there’s more potential to come in contact with the virus this way.

Syphilis can be severe or fatal if untreated. Severe symptoms can include:

Early treatment of syphilis with antibiotics, such as penicillin, is usually successful against bacteria. If you think you have syphilis, contact your healthcare provider for treatment as soon as possible to prevent any long-term complications.

Here’s a quick reference guide to some common STIs that don’t pass on through kissing:

  • Chlamydia. This bacterial STI is only spread through oral, anal, or genital sex without barrier methods. The bacteria isn’t transmitted through saliva.
  • Gonorrhea. This is another bacterial STI only passed on through sexual activity, not saliva from kissing.
  • Hepatitis. This is a liver condition typically caused by a virus that can be spread through sexual contact or exposure to blood that contains the virus, but not through kissing.
  • Pelvic inflammatory disease (PID). This is a bacterial infection spread through sexual contact. The bacteria can cause PID when introduced into the vagina, but not the mouth.
  • Trichomoniasis. This bacterial STI is only transmitted through genital sexual activity without barrier methods, not through kissing or even oral or anal sex.
  • HIV. This is a viral infection that isn’t transmitted through kissing. Saliva can’t transmit this virus. Contact with the following fluids can transmit HIV when they contain the virus:
    • semen
    • blood
    • vaginal fluid
    • anal fluid
    • breast milk

STDs can be a tricky, uncomfortable subject to talk about. Here are some tips for having a mature, productive discussion with your partner:

  • Set your expectations upfront. If you want your partner, whether new or longtime, to use barrier methods, tell them and be firm about it. It’s your body, and your partner has no right to tell you how to have sex.
  • Be direct, open, and honest. If you’re uncomfortable with having sex without first getting tested or using barrier methods, be clear about this and set the boundaries before you engage in any sexual activity. If you have an STI, let them know before having sex.
  • Use barrier methods. Condoms, dental dams, and other protective barriers not only have a high chance of preventing pregnancy but also shielding you against almost all STIs.
  • Above all, be understanding. Don’t get mad at your partner — or yourself — if you find out that either of you has an STI. Not all of them are spread through sex alone, so don’t assume that they’ve cheated on you or kept a secret from you. Some people don’t find out they have STIs until years later because of a lack of symptoms, so it’s important to trust your partner.

While most STI/STDs can’t be transmitted through kissing, there are some STIs that can spread this way, so it’s important to be aware of this before you kiss someone, so you can take proper precautions.

Communication is key: Discuss these things with your partner before you engage in any kind of sexual activity, and don’t be afraid to get tested or ask your partner to get tested. Open discussion like this can take away some of the anxiety and uncertainty and make the experience even more fulfilling.

If you’re concerned you might have an STI, see your healthcare provider right away before you have sex or engage in any related activity.