May 21, 2014
Oral sex involves giving or receiving oral stimulation (i.e., sucking or licking) to the penis (fellatio), the vagina (cunnilingus), or the anus (anilingus). HIV can be transmitted during any of these activities, but the risk is much less than that from anal or vaginal sex. Receiving fellatio, giving or receiving cunnilingus, and giving or receiving anilingus carry little to no risk. The highest oral sex risk is to individuals performing fellatio on an HIV-infected man, with ejaculation in the mouth.1,2
Even though oral sex carries a lower risk of HIV transmission than other sexual activities, the risk is not zero. It is difficult to measure the exact risk because people who practice oral sex may also practice other forms of sex during the same encounter. When transmission occurs, it may be the result of oral sex or other, riskier sexual activities, such as anal or vaginal sex.
If the person receiving oral sex has HIV, their blood, semen, pre-seminal fluid, or vaginal fluid may contain the virus. If the person performing oral sex has HIV, blood from their mouth may enter the body of the person receiving oral sex through the lining of the urethra (the opening at the tip of the penis), vagina, cervix, or anus, or through cuts and sores.
Several factors may increase the risk of HIV transmission through oral sex, including oral ulcers, bleeding gums, genital sores, and the presence of other sexually transmitted diseases (STDs).
In addition to HIV, other organisms can be transmitted through oral sex with an infected partner, leading to herpes, syphilis, gonorrhea, genital warts (human papillomavirus, or HPV), intestinal parasites (amebiasis), or hepatitis A or B infection.
The following things can reduce the risk of getting HIV through oral sex:
The risk of getting HIV from oral sex is lower if you are already taking pre-exposure prophylaxis (PrEP) consistently and correctly or if your partner is living with HIV and is taking antiretroviral therapy (ART) consistently and correctly. PrEP is a drug (Truvada) that can be prescribed to people at substantial risk of HIV to prevent infection. ART is a combination of drugs to treat HIV in people who already have HIV.
Keep in mind that barrier methods are the only way to protect against some STDs, including gonorrhea of the throat. Although the chance of getting or transmitting HIV from rimming (mouth to rectum) is small, there is a greater chance of transmitting hepatitis A and B, parasites, and other bacteria to the partner who is doing the rimming. There are effective vaccines that protect against hepatitis A and B and the human papillomavirus infections (HPV).
For information on reducing the risk of HIV infection from anal or vaginal sex or for information on PrEP, please visit the HIV Basics section.