Oral sex is generally a low risk activity. It is likely to be zero or close to zero in most circumstances. This will be higher depending on these factors:
- Whether you are receiving or giving oral sex?
Receiving oral sex (having someone’s mouth on your genital organs) is likely to be zero or near zero risk. Saliva is not linked to HIV transmissions.
- Whether you are giving oral sex to a man or a woman?
Giving oral sex to a woman is likely to be zero or close to zero risk. Cervical/vaginal fluid, even if infectious, is more difficult to get in your mouth compared to semen.
- Whether cum or pre-cum or gets in the mouth?
If there is no cum or no pre-cum then the risk is zero. But it can sometimes be difficult to know this.
- Oral hygiene of the person giving the oral sex?
The mouth is generally very resistant to infection, but cuts or sores, or bleeding gums, can be an easy route for infection.
Most cases reporting oral sex as a risk for HIV report mouth problems. Gum problems are common (perhaps in 10-50% of adults). If your gums bleed when you brush your teeth or floss this will be a route for HIV.
In practice, condoms are very rarely used for oral sex. This partly because condoms make oral sex so much less pleasurable for both partners and are more intrusive for oral compared to vaginal or anal sex. It is mainly because the risk from oral sex is believed to be so much lower that this is a risk people are happy to take.
If you don’t know your partners HIV status, or if they are HIV positive with a detectable viral load, then giving a man oral sex should be considered a potential risk for transmission. If you have poor oral health this risk may be high.
Up to 5% of HIV infections in gay men may be due to oral sex. These cases are likely to be explained by BOTH mouth/gum problems in the negative partner AND high viral load in the positive partner.
Last updated: 1 June 2016.