About STI Risk and Oral Sex

Key points

  • Many sexually transmitted infections (STIs) spread through oral sex.
  • Using a condom, dental dam, or other barrier methods the every time you have oral sex can reduce the risk of giving or getting an STI.
  • There is little to no risk of getting or transmitting HIV from oral sex.
abstracted collage of mouth and contagions

What it is

What is oral sex?

Oral sex involves using the mouth to stimulate the genitals or genital area of a sex partner. Types of oral sex include the penis (fellatio), vagina (cunnilingus), and anus (anilingus).

Oral sex is commonly practiced by sexually active adults. More than 85% of sexually active adults aged 18-44 years reported having oral sex at least once with a partner of the opposite sex. A separate survey conducted during 2011 to 2015 found that 41% of teenagers aged 15-19 years reported having oral sex with a partner of the opposite sex.

Signs and symptoms

What may increase the chances of giving or getting an STI through oral sex?

Certain factors may increase a person's chances of getting HIV or other STIs during oral sex if exposed to an infected partner. Factors like:

  • Poor oral health, which can include tooth decay, gum disease or bleeding gums, and oral cancer.
  • Sores in the mouth or on the genitals.
  • Exposure to the "pre-cum" or "cum" (also known as pre-ejaculate or ejaculate).

However, there are no scientific studies that show whether these factors increase the risk of getting HIV or STIs from oral sex.

Exposure risks

Which STIs can be passed on from oral sex?

  • Chlamydia (Chlamydia trachomatis)
  • Gonorrhea (Neisseria gonorrhoeae)
  • Syphilis (Treponema pallidum)
  • Herpes (herpes simplex virus types 1 and 2)
  • HPV (human papillomavirus)
  • HIV (human immunodeficiency virus)

How it spreads

Can STIs spread during oral sex?

Yes. Many STIs and other infections are spread through oral sex. Anyone exposed to an infected partner can get an STI in the mouth, throat, genitals, or rectum. The risk of getting an STI or spreading an STI to others through oral sex depends on several things, including the particular STI, type of sex, and number of sex acts performed.

In general:

  • It is possible to get some STIs in the mouth or throat after giving oral sex to a partner who has a genital or anal/rectal STI.
  • It is possible to get certain STIs on the genitals and genital areas after receiving oral sex from a partner with a mouth or throat infection.
  • It is possible to have an STI in more than one area at the same time. For example, you can have an STI in the throat and the genitals.
  • Several STIs (i.e., syphilis, gonorrhea, and intestinal infections) that are transmitted by oral sex can spread in the body.
  • Oral sex involving the anus (or anilingus) can transmit hepatitis A and B. It also can transmit intestinal parasites like Giardia and bacteria like E.coli and Shigella.
  • If you have an STI, you might not know it because many STIs are symptomless. It is possible to spread STIs even when you don't have any signs or symptoms.

Reducing risk

Is oral sex safer than vaginal or anal sex?

  • It is difficult to compare the risks of getting specific STIs from specific types of sexual activity
  • Most people who have oral sex also have vaginal or anal sex
  • Few studies look at the risks of getting STIs, other than HIV, from giving oral sex on the vagina or anus, compared to the penis
  • Studies show the risk of getting HIV from oral sex (giving or receiving) with a partner who has the infection is much lower than the risk of getting HIV from anal or vaginal sex. This may not be true for other STIs.
  • In a study of gay men with syphilis, 1 out of 5 reported having only oral sex.
  • Getting HIV from oral sex may be extremely low, but it is hard to know the exact risk. If you are having oral sex you should protect yourself.
  • It is possible that getting certain STIs in the throat like chlamydia or gonorrhea may not be as harmful as getting an STI in the genital area or rectum. Having these infections in the throat might increase the risk of getting HIV. Having gonorrhea in the throat also may might lead to the spread of disease throughout the body. In addition:
  • Having infections of chlamydia and gonorrhea in the throat may make it easier to spread these infections to others through oral sex. This is especially important for gonorrhea, since throat infections can be harder to treat.
  • Infections from certain STIs, such as syphilis and HIV, spread throughout the body. Therefore, infections acquired in the throat may lead to the same health problems as infections acquired in the genitals or rectum.
  • Mouth and throat infections by certain types of HPV may develop into oral or neck cancer.

What can you do to prevent STI transmission during oral sex?

You can lower your chances of giving or getting STIs during oral sex. Use a condom, dental dam or other barrier methods every time you have oral sex.

  • For oral sex on the penis:
    • Cover the penis with a non-lubricated latex condom.
    • Use plastic (polyurethane) condoms if you or your partner is allergic to latex.
  • For oral sex on the vagina or anus:
    • Use a dental dam.
    • Cut open a condom to make a square and put it between your mouth and your partner's vagina or anus.

The only way to avoid STDs is to not have vaginal, anal, or oral sex.

If you are having sex, you can lower your chances of getting an STD by:

  • Being in a long-term mutually monogamous relationship with a partner who does not have an STD (e.g., a partner with negative STD test results).
  • Using latex condoms the right way every time you have sex.

It's important to remember that many people with an STD may be unaware of their infection. STDs often have no symptoms and are unrecognized.

Testing

If you are having sex, ask your healthcare provider to test you regularly for STDs and HIV. Talk openly with your provider about activities that might put you at risk for an STD, including oral sex. You also should talk to your partner(s) about STDs. Free and low-cost options for testing are available in your area.

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National Center for HIV, Viral Hepatitis, STD, and Tuberculosis Prevention; About Division of STD Prevention
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