Can You Get an STI From Kissing? Here's What You Should Know

You probably do your best to avoid sexually transmitted infections (STIs, formerly known as STDs) by using condoms and talking with your healthcare provider about STI testing. But what about kissing—can you get an STI from lip contact? You may be surprised to learn that, yes, some STIs can be spread through kissing.

"This is something that isn't discussed a lot, but it's good to know about," said Christine Greves, MD, OB-GYN at the Winnie Palmer Hospital for Women & Babies in Orlando, Florida.

Since this likely wasn't covered in your high school sex ed class, we checked with the experts to learn more. Here's what they told us.

Can STIs Be Spread Through Kissing?

It's borderline mind-blowing, but yes, you can get an STI from kissing. "There are STIs that can be spread through non-sexual contact [like kissing] that are also spread through sexual contact," said Martha Rac, MD, assistant professor of obstetrics and gynecology at Baylor College of Medicine.

The overall risk of getting an STI from kissing is fairly low, but it is something that legitimately happens.

"This is definitely a possibility, and there are some STDs that we worry about more than others when it comes to kissing," said Michael Angarone, DO, associate professor of infectious diseases at the Northwestern Feinberg School of Medicine.

In general, healthcare providers say you're more at risk from mouth-to-mouth kissing, but there are some STIs (looking at you, herpes) that can be passed on by kissing someone's cheek, head, and even eyes, Dr. Greves said.

Which STIs Can You Get From Kissing?

Here's a breakdown of STIs that can be spread through mouth-to-mouth contact.

Herpes

Herpes is caused by two similar viruses—herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). Both can be transmitted by kissing.

HSV-1 typically causes cold sores (also known as fever blisters) on or around your mouth. It is often referred to as oral herpes. A survey from the Centers for Disease Control and Prevention (CDC) found that 47.8% of people 14 to 49 years old have HSV-1.

Most people with HSV-1 were infected as a child or young adult from non-sexual contact with saliva, like kissing. You can have HSV-1 without any symptoms at all.

HSV-2 is traditionally known as genital herpes. However, HSV-2 can also cause oral herpes sores. "Sometimes, if you practice oral sex, you can get HSV-2 around your mouth," Dr. Greves said.

Oral HSV-2 can then be spread through mouth-to-mouth contact. Still, "it's rarer to get HSV-2 from kissing than HSV-1," Dr. Angarone said.

HSV-1 and HSV-2 are typically only contagious during an outbreak. "The greatest risk of transmission is when active lesions—cold sores on the mouth—are present," Dr. Rac said.

Syphilis

Though extremely rare, syphilis can be spread through kissing. The STI is spread by direct contact with a syphilis sore—and those sores can be found on or around the penis, vagina, anus, rectum, lips, or mouth. Symptoms can include:

• Firm, round, and painless sores at the site of infection
• A skin rash
• Swollen lymph nodes
• Fever

The risk of contracting syphilis from kissing is pretty slim. While it can happen, "oral syphilis is very rare," Dr. Greves said.

How Are Oral STIs Treated?

It depends on the condition. HSV-1 and HSV-2 can be treated with antiviral medications like acyclovir, famciclovir, and valacyclovir. But while these medications can help reduce symptoms and the frequency of outbreaks, antivirals can't cure this chronic, lifelong infection.

Syphilis can be cured with an injectable form of penicillin. If syphilis is diagnosed at a later stage, more than one injection might be needed.

How Do You Prevent STIs From Kissing?

Preventing oral STIs is a little tricky. You're unlikely to ask for someone's full sexual history before the first kiss. Still, healthcare providers say there are a few smart ways to lower your risk.

• Don't kiss someone with a cold sore. While it's possible to get herpes and syphilis through kissing when someone doesn't show any signs of the STI, it's most likely to happen when you can actually see a sore, Dr. Angarone pointed out. "You should not be kissing anyone who has an active oral ulcer," Dr. Angarone said.
• Practice monogamy. Being monogamous with one partner who doesn't have STIs means you won't be exposed to them, Dr. Greves pointed out.
• Ask questions. Again, kissing tends to happen spontaneously, and it's unlikely that you'll have a big conversation about sexual history before kissing someone. But Dr. Greves noted that it's more than OK to ask about their sexual health before you kiss them—and to be open about your own sexual health history.

A Quick Review

Overall, healthcare providers stress that your risk of getting an STI from kissing is fairly low. But if your date has an obvious sore on or around their lips, it's best to take a pass on making out until it heals, just to be safe.