If you’re living with HIV or AIDS, you may worry about spreading the virus to partners through sex. You may also wonder whether different types of sexual activity are “safer,” or less likely to cause HIV, than others. In particular, myHIVteam members and other people living with HIV often question whether oral sex can transmit (pass) the virus to partners.

With these concerns in mind, many people living with HIV want to safely have intimate sexual relationships. If you’re unsure whether it’s safe to have oral sex after being diagnosed with HIV, read on to learn the facts about HIV and oral sex, as well as tips for safer oral sex. Talk with your doctor or HIV care team if you have questions about oral sex, your sexual health, or your partner’s sexual health.

1. You Can Transmit HIV Through Oral Sex, But It’s Rare

It’s technically possible to transmit HIV through oral sex, but compared with other types of sex, the risk is very low. Even though researchers say the risk of HIV transmission through oral sex is almost zero when someone uses HIV medicine, PrEP (preexposure prophylaxis, medications to help prevent getting HIV), and/or condoms, it is incorrect to say that there is absolutely no risk in every situation.

What Is the Chance of Getting HIV Through Oral Sex?

Researchers say that the chances of transmission lie somewhere between zero percent and 0.04 percent (a 4-in-10,000 chance). This estimate is based on studies that looked at real couples where one person had HIV and the other didn’t to see how often the virus was passed during different kinds of sexual activities.

The odds are lower than the chances of transmission through other sex acts, such as anal or vaginal sex. Although the exact risks of transmission through these routes are unknown, the percentages are much higher than those for oral sex.

It’s important to note that, in these statistics, a person’s biological sex doesn’t seem to matter. It may be that oral sex transmits HIV so rarely that too few cases can be studied to determine such details. At this time, research indicates that transmission via oral sex is very unlikely, regardless of whether the HIV-negative partner was assigned male or female at birth.

2. Several Factors Raise the Risk of Transmitting HIV Through Oral Sex

A few situations make it more likely that a person may transmit HIV in the exchange of bodily fluids during oral sexual contact.

For example, oral sexual activity with a partner who is HIV-positive and has a detectable viral load (enough of the virus found in their blood that it shows up on tests) makes transmission more likely. Regular testing can show whether a person has a detectable or undetectable viral load.

Transmission is also possible if someone living with HIV ejaculates into their partner’s mouth during oral sex. Additionally, HIV is more likely to spread if either partner has another oral sexually transmitted infection (STI, also known as a sexually transmitted disease or STD), like gonorrhea, chlamydia, syphilis, or herpes of the mouth, lips, or throat.

If the HIV-negative partner has open sores or ulcers in their mouth, bleeding gums, or an illness causing sores or inflammation in the throat, transmission is more likely. Also, if the HIV-positive partner has sores, infections, or inflammation on their genitals, there is a higher chance that HIV will pass from that partner to the HIV-negative partner, including via oral sex.

Performing oral sex on someone who is HIV-positive and menstruating also raises the risk of transmission through blood in their vaginal fluids, though only very slightly.

3. Antiretroviral Therapy Helps With HIV Prevention

HIV treatments known as antiretroviral therapy (ART) help keep the virus under control. There are several varieties of these HIV medicines, and your healthcare provider can help you find the one that works best for you with the fewest side effects.

Over time, these drugs should lower the amount of the virus in the body to a very low or even undetectable level. At these levels, a person’s chances of transmitting HIV to a partner through sex — whether oral, anal, or vaginal — are basically zero.

4. PrEP Lowers the Risk of Transmission

Preexposure prophylaxis (PrEP) is a type of drug given to help prevent uninfected people from getting HIV. Someone who is HIV-negative can take PrEP to significantly lower their chances of contracting HIV. PrEP comes in two forms — as a daily pill or as an injection you get every two months. PrEP is not for people who already have HIV.

No studies have specifically looked at the use of PrEP in preventing transmission during oral sex. However, based on the way the medications work to prevent infections from other causes, medical researchers believe these drugs would also help prevent transmission via oral sex. When taken correctly, PrEP can lower the chance of getting HIV by more than 99 percent.

PrEP helps many couples stay physically intimate with each other well after an HIV diagnosis. One myHIVteam member shared that their partner said that they would go on PrEP: “We will always love each other with your HIV meds and me being on PrEP.”

Although their names are easy to confuse, postexposure prophylaxis (PEP) and preexposure prophylaxis (PrEP) are not the same. Unlike PrEP, which you can take to decrease the risk of getting HIV, PEP is a medical treatment you take if you believe you have already been exposed to the virus. PEP is generally less effective than PrEP, and it must be taken within 72 hours of exposure to HIV to work. No published study findings address the effectiveness of PEP specifically taken only after oral sex.

5. Physical Barriers Reduce the Chances of Transmission

Physical barriers like condoms can also help prevent the risk of HIV transmission during oral sex. If an HIV-negative partner doesn’t take PrEP, if the HIV-positive partner has a detectable viral load, or if you want to take extra precautions, these approaches can help prevent HIV transmission during oral sex.

People with penises should use condoms, as it is very difficult for HIV to pass through latex, as long as the instructions are followed properly and the condom is not expired or damaged. Partners who want additional protection can use dental dams — square pieces of latex that are placed over the partner’s anus or vagina during oral sex. You also can cut a condom lengthwise and use it in the same way as a dental dam for similar protection.

These methods offer the bonus of protecting both partners from other sexually transmitted diseases, too.

Talk to Your Doctor

If you’ve been diagnosed with HIV and want to have sexual relationships, talk to your doctor about how to do so safely. They can provide you with the health information that’s right for you and your partner. Between HIV treatment for you and PrEP for your partner or partners, as well as the other protective methods described in this article, you should be able to continue being sexually intimate.

Before being sexually active, if you are HIV-positive, you may need to wait for your antiretroviral treatment to work or for your HIV-negative partner’s PrEP to take effect. According to the New York State Department of Health, you must take the PrEP pill for seven consecutive days to protect you during anal sex or 20 consecutive days to protect you during vaginal sex. Injectable PrEP starts working quickly — about half of people are protected one day after the first injection, and almost everyone is protected about seven days after the first injection.

Talk to your doctor about how long to wait based on the type of PrEP you use. Your doctor can help you choose between the pill and injection based on what works best for your lifestyle.

Talk With Others Who Understand

On myHIVteam, the social network for people with HIV and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with HIV.

Are you living with HIV and want to learn more about how the disease is transmitted? Are you concerned for your sexual partners, or do you want to learn more about HIV and oral sex? Share your experience in the comments below, or start a conversation by posting on your Activities page.