Oral Sex: What's the Real Risk for HIV?

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The chances of HIV being passed from one person to another depend on the type of contact. HIV is most easily spread or transmitted through unprotected anal sex, unprotected vaginal sex, and sharing injection drug equipment. Unprotected sex means sex in which no condoms, other barriers, or treatment-as-prevention methods (different ways of using HIV drugs to lower risk of HIV transmission) are used.

Oral sex involves contact between the mouth and the genitals. It includes giving or receiving licking, sucking, or biting of the vulva (vagina, clitoris, and labia, or "lips"), penis, or anus. Under most circumstances, oral sex poses little to no risk of spreading HIV. Oral sex may not be risk-free, but it has been shown to be much less risky than the activities described above.

HIV is present in female sexual fluid (vaginal secretions), male sexual fluids ("cum" and "pre-cum"), and blood. HIV cannot be spread through saliva (spit). One of these other fluids must be present, and there must be a way for them to enter the HIV-negative person's bloodstream (such as mouth sores or genital ulcers), for HIV transmission to be possible.

It is possible to get other sexually transmitted infections or diseases (STIs or STDs), such as syphilis, herpes, gonorrhea, and human papilloma virus (HPV) through oral sex. HIV treatment as prevention does not protect against STIs other than HIV.

Studies on the Risks of Oral Sex

Oral sex is a low-risk activity for HIV. Factors that increase the risk of HIV transmission through oral sex include having bleeding gums, mouth ulcers, gum disease, genital sores, and other sexually transmitted infections. Several reports suggest that people have acquired HIV through oral sexual activity in rare instances. A number of studies have tried to figure out the exact level of risk of oral sex, but it can be difficult to get accurate information. When HIV is spread, it is difficult to tell if it was the oral sex or another, more risky sexual activity that was responsible for transmitting HIV.

The take home message is that oral sex may, under certain circumstances, carry a small but real risk of HIV transmission.

Tips for Safer Oral Sex

Oral sex is more risky if you or your partner:

  • has an untreated sexually transmitted infection
  • has bleeding gums, mouth ulcers (open sores), or gum disease
  • takes ejaculate (semen, or cum) in the mouth
  • puts your mouth on the genitals of a woman who is menstruating (bleeding)
  • has genital sores

There are things you can do to lower the risk associated with oral sex:

  • Do not have oral sex if you or your partner has mouth sores (such as oral herpes lesions)
  • Look at your partner's genitals for lesions (cuts, scrapes, or sores)
    • If you find something, avoid contact with the area until a health care provider examines it. Very rarely are genital lesions the result of the heat, the weather, or someone's clothes.
  • Do not floss, brush your teeth, or do anything that would create cuts or cause bleeding in your mouth before performing oral sex. Use a breath mint instead.
  • Avoid swallowing pre-cum, semen, vaginal fluids, or menstrual blood
  • Use latex condoms for oral sex on a man (fellatio)
    • Try the flavored ones that come without lube on them
    • If you perform oral sex without a condom, finish up with your hand, or spit semen out rather than swallowing it
  • Use a dental dam or cut-open condom for oral sex on a woman (cunnilingus) or for rimming (licking the anus)
    • Dental dams are squares made from latex. Put some water-based lube on one side of the dental dam, or a condom that has been cut open. Then stretch the dam or condom over the vulva or anus with the lubed side facing down. This gives you a thin barrier between your mouth and the vagina or anus. Some people use plastic food wrap as a barrier. While plastic wrap has been shown to prevent the transmission of herpes infections, there has been no research on its effectiveness in preventing HIV transmission.
  • Avoid vaginal oral sex when a woman is menstruating (having her period or cycle) to prevent contact with blood
  • Take care of your mouth. The chances of getting HIV from oral sex increase if you have bleeding gums, ulcers, cuts, sores, or infections in the mouth.
  • Use alternatives
    • Try massage or mutual masturbation
    • Try a vibrator (use a condom and put on a new condom when sharing)
  • Avoid giving a man oral sex if his penis is bruising your throat or tonsils (sometimes caused by "deep-throating"), or if you experience injuries around your mouth

Taking Care of Yourself

While the risk of becoming infected through unprotected oral sex is lower than that of unprotected anal or vaginal sex, it is not risk-free. If you or your partner is living with HIV (HIV+), it is important that you decide what steps to take to make all types of sex safer (see our fact sheet on safer sex). It is also important to remember that having bleeding gums, mouth ulcers, or gum disease and taking cum or menstrual blood in your mouth can make oral sex more risky. If you would like to discuss these issues, see a sex educator or health care provider at your local AIDS service organization (ASO) or treatment center. To find an ASO in your area, click here. For services worldwide, please use AIDSmap's e-atlas.

Adapted from original article written by LM Arnal.