Oral sex is the act of using your mouth, lips, or tongue to stimulate a partner’s genitals or anus. It is one of the most common forms of sexual activity, practiced across all demographics and relationship types. While many people think of it as lower risk than intercourse, oral sex still carries health considerations worth understanding.
The Three Types of Oral Sex
Oral sex falls into three categories based on which body part is being stimulated. Fellatio involves stimulating a penis with the mouth and tongue. Cunnilingus involves stimulating the vulva and vagina with the mouth and tongue. Anilingus, sometimes called rimming, involves oral contact with the anus.
Any of these can be performed as a standalone sexual activity or as part of a broader sexual encounter. Oral sex can also be mutual, with both partners giving and receiving at the same time.
STIs That Can Spread Through Oral Sex
A common misconception is that oral sex is “safe” in the sense that infections can’t pass between partners. That’s not accurate. The CDC lists six infections that can be transmitted through oral sex: chlamydia, gonorrhea, syphilis, herpes (both type 1 and type 2), HPV, and HIV. The risk level varies significantly depending on the infection. HIV transmission through oral sex is classified as extremely low to negligible, while herpes and HPV spread more readily because they transmit through skin-to-skin contact rather than only through fluids.
Anilingus carries additional risks beyond those six. Oral contact with the anus can transmit hepatitis A and B, intestinal parasites like Giardia, and bacteria including E. coli and Shigella. These spread through the fecal-oral route, even when the area appears clean.
Throat infections from gonorrhea and chlamydia are particularly worth knowing about because they often produce no symptoms. You can carry and transmit a throat infection without realizing it, which is one reason regular STI screening matters if you’re sexually active with new or multiple partners.
The HPV and Cancer Connection
HPV deserves special attention because of its link to throat and mouth cancers. About 70% of cancers in the oropharynx (the back of the throat, base of the tongue, and tonsils) are caused by HPV, according to CDC cancer registry data from 2018 to 2022. That amounts to roughly 16,000 cases per year in the United States. Men are disproportionately affected: around 13,600 of those annual cases occur in males, compared to about 2,400 in females.
HPV vaccination significantly reduces the risk of these cancers. The vaccine is most effective when given before a person becomes sexually active, but it’s approved for adults up to age 45.
How to Reduce Risk
Barrier methods are the most effective way to lower the chance of infection during oral sex. For fellatio, an unlubricated or flavored condom works as a barrier. For cunnilingus and anilingus, a dental dam provides protection. Dental dams are thin sheets of latex or polyurethane placed flat over the vaginal opening or anus before oral contact begins.
A few practical points on dental dams: use a new one every time, check for tears before use, and apply water-based or silicone-based lubricant on the side touching the body to prevent tearing. Oil-based products like lotion, petroleum jelly, or cooking oil will break down latex and should never be used. If you don’t have a dental dam available, you can make one by cutting the tip and base off a latex or polyurethane condom and then cutting down one side to create a flat sheet.
Timing your oral hygiene also matters. Brushing, flossing, or using mouthwash can create tiny cuts or abrasions in your gums and mouth lining. Those micro-wounds give infections an easier path into your bloodstream. If you know oral sex is likely, it’s better to brush well before (giving your gums time to settle) or simply rinse with water beforehand rather than brushing immediately prior.
Communication and Consent
Consent for oral sex follows the same principles as any sexual activity. It needs to be affirmative, clear, and ongoing. Agreeing to one type of sexual contact doesn’t imply agreement to another, so transitioning from kissing to oral sex, or from one type of oral sex to another, requires checking in with your partner. Consent can also be withdrawn at any point. If someone pulls away, says they’re uncomfortable, or gives any verbal or physical signal that they want to stop, that ends consent regardless of what was agreed to earlier.
Beyond consent, open conversation about preferences makes the experience better for both people. Talking about what feels good, what’s off limits, and whether barrier methods will be used removes guesswork and builds trust. These conversations can happen before, during, or after sexual activity, and they tend to get easier with practice.