This blog was first published on 10/06/2022. Last updated 14/03/2025.
Sex comes with risks. From unwanted pregnancies to STIs, having sex without taking proper precautions can feel like stepping onto a road without looking both ways. You might be OK, but would you do it?
So, it makes sense that people would have questions about the dangers of sex, and in particular about the infections that can seriously damage your health.
For decades now, HIV has been the STI bogeyman that has spooked so many people out of having sex. It makes sense that people who are worried about it would want to know how they can get it.
While most people know that you can get HIV from sex, oral sex seems to be a blind spot in most people’s knowledge.
Can HIV be transmitted through oral sex?
The answer is a bit complicated. Keep reading to find out more.
You can have HIV and not know it. Get tested with one of Better2Know’s Home Test Kits.
What is HIV?
To understand whether HIV can be transmitted through oral sex, we need to quickly explain what it is.
HIV (Human Immunodeficiency Virus) is a retrovirus that attacks the immune system by reducing the number of your CD4 cells, which are crucial for fighting off infections.
If left untreated, HIV can lead to AIDS (Acquired Immunodeficiency Syndrome), a condition where the immune system becomes severely compromised, making the body vulnerable to various illnesses.
In 2023, 39.9 million around the world people were living with HIV. During the same year, 1.3 million people became newly infected with HIV, and 630,000 people died from AIDS-related illnesses.
In the UK, 102,168 people received HIV care in 2022, with 4,040 people newly diagnosed with HIV that year. The majority of people accessing HIV care in the UK acquired HIV through sexual transmission, accounting for 95.4% of cases.
How is HIV transmitted?
HIV is transmitted between people through specific infected bodily fluids. These fluids include blood, semen (including pre-cum), vaginal secretions, and breast milk.
Transmission can occur in one of two ways: sexually and non-sexually.
Non-sexual transmission
You can get HIV from a variety of non-sexual means, including:
- Sharing needles when injecting drugs can pass on many blood-borne infections, including HIV. It is a high-risk activity as it allows for direct blood-to-blood contact. Mothers can transmit HIV to their babies during pregnancy, childbirth, or breastfeeding.
- Blood transfusions can pose a risk in areas where blood supplies are not routinely screened.
- Needle stick injuries can be a risk for healthcare workers who can be regularly exposed to needles on the job.
- A mother’s breast milk can transmit HIV to their child during breastfeeding. This is called vertical transmission.
- Unsterilised tattooing equipment cantransmit the virus.
Sexual transmission
HIV can be transmitted through unprotected sexual activities, including:
- Vaginal sex
- Anal sex
- Oral sex (less common)
Are there different risks for different types of sex?
You’re more likely to get HIV if you perform certain types of sex.
Vaginal sex
Vaginal sex is an effective way for HIV to transmit. HIV can concentrate in high levels in vaginal secretions and semen. Genital tissues are also highly susceptible to infections if they come in contact with pathogens.
A meta-analysis of studies of unprotected heterosexual HIV transmission found that there was a 0.04% chance of transmission if the female partner is positive and the male partner is negative. The risk rises to 0.08% when the male partner is positive, and the female partner is negative.
Anal sex
The likelihood of contracting HIV through anal sex is higher compared to vaginal sex. This is because the anus is less pliable and more prone to tearing.
For unprotected anal intercourse, the estimated risk of HIV transmission is:
- 1.38% for receptive anal sex (when the person is receiving the penis). This means there is approximately one transmission per 72 exposures.
- 0.11% for insertive anal sex (when the person is inserting the penis). This translates to about one transmission per 909 exposures.
These risks can be significantly reduced if the HIV-positive partner is on effective antiretroviral treatment and has an undetectable viral load, or if condoms are used consistently.
Oral sex
Oral sex is the least likely form of sexual transmission for HIV. Few studies exist that track the transmission of HIV through oral sex since it’s difficult to find people whose only risk of HIV transmission is unprotected oral sex.
However, the NHS states that, while there’s still a chance that you can get HIV from oral sex, the risk is comparatively much smaller than anal and vaginal sex.
The risk differs based on the kind of oral sex being performed and who has the infection.
- Receiving oral sex from someone with HIV: While technically possible, it’s extremely unlikely to get HIV from someone who performs oral sex on you. Passing on the infection in this manner is only possible if the infected person has cuts or mouth ulcers, which made their mouth bleed.
- Performing oral sex on someone with HIV: There’s a small risk of transmission if someone who is HIV-negative performs oral sex on a person with a penis who has a detectable viral load of HIV. The risk increases if pre-cum of semen enters the other person’s mouth
Oral-vaginal sex has even lower risk factors. No cases of HIV being transmitted through this method have been recorded, but it’s theoretically possible if the woman receiving cunnilingus is HIV positive and menstruating.
Anilingus, or oral-anal sex, has similarly low risks when it comes to HIV transmission.
When does the risk for HIV transmission during oral sex rise?
Several factors could raise the risk of HIV transmission during oral sex. These include:
- A higher viral load: If the HIV-positive partner has a higher viral load, then the chances of transmission increase.
- Sores in the mouth: Having ulcers or cuts in the mouth may make oral sex riskier.
- When a woman is menstruating: Similarly, menstruation may make HIV transmission more likely.
- Having another STI: Having an STI like Chlamydia or Gonorrhoea can increase the risk of HIV, especially if you have an STI like herpes that causes sores on the skin.
- A throat virus or infection: Having a virus or infection of the throat can make HIV transmission more likely. Nevertheless, the chances are still very low.
How can I protect myself?
The best way to protect yourself from HIV, or any other STI, is to practice safe sex.
Here are some tips:
- Use condoms and dental dams during oral sex. Barrier methods of contraception can help decrease the transmission of sexually transmitted diseases.
- Get tested for STIs. If you’ve had a sexual encounter with a new partner, protect yourself by selecting an STI test to verify your status.
- Consider pre and post-exposure prophylaxis. Use pre-exposure prophylaxis daily if you’re sexually active with someone who’s HIV positive. A post-exposure prophylaxis is a wise measure after an encounter with a partner with an uncertain HIV status.
Final thoughts
The risk of becoming infected with HIV through oral sex is very low. However, certain factors mentioned above increase the risk.
Getting tested for STIs regularly and before any new partner to verify your status is always a good idea. If you have had sexual contact with a partner with HIV, you should take a test as soon as possible.
Don’t leave your sexual health to chance. Get tested with Better2Know today.