Oral sex carries a lower risk of sexually transmitted infections than vaginal or anal sex, but the risk isn’t zero. Gonorrhea, syphilis, herpes, HPV, and chlamydia can all be transmitted through oral contact with a partner’s genitals or anus. The good news: a few straightforward habits can reduce that risk significantly.
Which Infections Spread Through Oral Sex
Gonorrhea is one of the most easily transmitted STIs during oral sex. It can infect the throat (pharyngeal gonorrhea), often without causing any noticeable symptoms, which means you can carry and spread it without knowing. Syphilis can also pass through oral contact if a sore is present on the mouth or genitals. Herpes (both HSV-1 and HSV-2) spreads through skin-to-skin contact, so a cold sore on the lip can transfer the virus to a partner’s genitals and vice versa.
HPV deserves special attention. Oral HPV infection is now a leading cause of throat and mouth cancers, particularly in men. These cancers have been rising steadily, and because HPV infections produce no symptoms for years, many people never realize they’ve been exposed.
HIV transmission through oral sex is a different story. The CDC describes the risk as “little to no risk,” and while it’s theoretically possible, the actual transmission rate is extremely low compared to vaginal or anal sex.
Use Barrier Methods
Condoms and dental dams are the most effective way to reduce STI risk during oral sex. For oral sex on a penis, use a non-lubricated or flavored condom. For oral sex on a vulva or anus, use a dental dam, which is a thin sheet of latex or polyurethane placed flat over the area.
The CDC recommends the following when using a dental dam:
- Use a new one every time. Never reuse a dental dam.
- Check the packaging. Look at the expiration date and inspect for tears or defects before use.
- Place it before you start and keep it in place until you’re finished.
- Add water-based or silicone-based lubricant on the side touching skin to prevent breakage and improve sensation.
- Don’t stretch it. Stretching can cause tearing.
- Avoid oil-based products. Baby oil, lotion, petroleum jelly, and cooking oil will break down latex.
Dental dams can be hard to find in stores. If you don’t have one, you can make one from a standard condom. Start with a non-lubricated or flavored condom, check the expiration date, then unroll it fully. Using scissors, cut off the tip and the rim, then cut down one side lengthwise. You’ll have a flat rectangular sheet that works the same way.
Skip Brushing and Flossing Beforehand
This one surprises most people. Brushing or flossing your teeth right before or after oral sex creates tiny abrasions in your gums that give bacteria and viruses an easier entry point. If you want to freshen up, rinse with water or use a mouthwash instead. The same logic applies to any recent dental work, mouth piercings, or existing gum disease: anything that breaks the skin inside your mouth can increase your vulnerability to infection.
Get Vaccinated Against HPV
The HPV vaccine is one of the most powerful tools for reducing the long-term risks of oral sex. It prevents infection from the HPV strains most likely to cause cancer, but it only works before you’ve been exposed to those strains. That’s why it’s recommended primarily for younger people, ideally before they become sexually active.
The impact is real. Researchers at Johns Hopkins projected that oropharyngeal cancer rates will nearly halve between 2018 and 2045 among vaccinated age groups. By 2045, an estimated 1,000 cases of throat cancer per year will be prevented in the U.S. alone. If you’re under 26 and haven’t been vaccinated, it’s worth prioritizing. Adults up to age 45 can also discuss vaccination with a healthcare provider, though the benefit decreases with age and prior sexual exposure.
Get Tested Regularly
Many oral STIs produce no symptoms at all. Pharyngeal gonorrhea in particular often goes undetected unless you specifically request a throat swab. Standard STI panels don’t always include oral testing, so you may need to ask for it.
Current CDC guidelines recommend that men who have sex with men get screened for gonorrhea at the throat at least once a year, regardless of condom use, and every three to six months if they have multiple partners, are on PrEP, or are living with HIV. For women and transgender individuals, throat screening is recommended based on sexual history and exposure. If you’re giving oral sex regularly, especially with new or multiple partners, tell your provider so they can test the right sites.
Choose Lubricants Carefully
Flavored lubricants are marketed specifically for oral sex, and most are safe when small amounts are swallowed. Water-based options are the most common and generally the gentlest. Their main ingredients are humectants like glycerin and propylene glycol, which keep them from drying out quickly.
A few things to watch for: some products add capsaicin, menthol, or caffeine for a “tingling” sensation, which can cause irritation on sensitive tissue. Others contain numbing agents like lidocaine, which can mask pain that might otherwise alert you to a problem. Silicone-based lubricants are also safe for oral contact in small amounts since silicone isn’t absorbed by the body. Avoid oil-based lubricants if you’re using latex condoms or dental dams, because oil degrades latex.
The FDA doesn’t regulate personal lubricants like medications, so there’s no standardized safety testing. Stick with well-known brands, read ingredient lists, and stop using anything that causes irritation.
Reduce Risk Without Barriers
Realistically, many people don’t use barriers during oral sex. If that’s the case, a few practices still lower your risk. Avoid oral sex when you or your partner has visible sores, blisters, or unusual discharge on the mouth or genitals. Reduce the number of partners you have unprotected oral sex with. Avoid contact with semen or vaginal fluid when possible, as this limits exposure to certain infections. And keep up with regular STI screening so that if something is transmitted, it’s caught and treated early before it spreads further.
Communicating with partners matters too. Asking about recent test results and sharing your own isn’t awkward, it’s practical. Many STIs are curable with a short course of antibiotics when caught early, and the ones that aren’t (like herpes and HPV) are far more manageable when both partners know what they’re dealing with.