HIV risk from oral sex

How low is the risk?

Of all the ways people have sex, oral sex carries the least HIV risk. CDC rates it as low rather than giving a single precise figure. The calculator uses an estimate of 0.01% (about 1 in 10,000) per act when the partner has HIV and isn’t on treatment.

With a partner whose status you don’t know, the chance is far smaller, because that person most likely doesn’t have HIV. In the United States, for example:

• A woman giving oral sex to a man of unknown status: <0.0001% (about 1 in 5,800,000)
• A man giving oral sex to a man of unknown status: 0.00036% (about 1 in 280,000)

The second figure is higher only because HIV is more common among men who have sex with men. The act itself carries the same low risk.

Giving vs receiving

Giving oral sex (your mouth on a partner’s penis or vagina) means contact with semen, pre-cum or vaginal fluid. These fluids can carry HIV, but CDC still says oral sex carries little to no risk.

Receiving oral sex means contact with your partner’s saliva. HIV is not passed on through saliva, so receiving oral sex also carries very little risk.

If your partner has HIV and keeps an undetectable viral load on treatment, they don’t pass HIV on through sex, oral sex included. See U=U.

Ejaculation, cuts and ulcers

CDC says ejaculation in the mouth, combined with mouth ulcers, bleeding gums or genital sores, can increase the chance of HIV passing during oral sex. Other STIs can too. Even then, the risk stays low.

• No ejaculation in the mouth. The calculator lowers the estimate by 50% when a male partner didn’t ejaculate in your mouth.
• Other STIs. Sores and inflammation from another infection make it easier for HIV to get in. The calculator multiplies the estimate by 2 if either of you has one.

Rimming

CDC counts oral contact with the anus, often called rimming, as a type of oral sex, and puts oral sex in its “little to no risk” group for HIV. It can pass on other infections, though.

Other STIs are more of a concern

HIV is rarely the main risk from oral sex. CDC notes you can get other STIs from oral sex. If you have symptoms, or you’re getting checked anyway, tell the clinician about oral sex so they can decide which tests you need. Our page on HIV and STIs explains how the two connect.

What to do now

1. If it was only oral sex, your risk is very low. For most people, a test at the right time is enough reassurance.
2. If other types of sex happened too, those usually carry more risk than the oral sex. Use the calculator with every act included.
3. Test after the window period. A lab antigen/antibody test (blood from a vein) gives a conclusive negative result from 45 days after the exposure. See test accuracy by week.
4. Look after your peace of mind. Worry after oral sex is common, even though the risk is very low. If it’s taking over, see our page on HIV anxiety.