If you’re sure of your clean bill of health, then oral sex isn’t dangerous. If you’re unsure, or if one of you has an STI, then oral sex puts you at risk of transmission.
Oral sex is generally safe, although there is a risk of transmission of sexually transmitted infections. Basic safe-sex practice applies: If you've had sex with other people in the past, you may want to get tested. If you're both clean, that's great - there's little chance that you can contract something from oral sex.
Often, however, things are not so clear. You or your partner may have an STI that you don't know about. One of you may not be 100% truthful about their sex life or romantic history. If someone is infected with something, then oral sex gets riskier.
You're at the most risk of giving or receiving an STI if one of you has a cut, sore, or abrasion in the mouth or the throat. That puts you at higher risk of contracting an STI in general. Some STIs - such as HIV - can only be contracted through oral sex if there's an abrasion in the mouth or throat. Cases of HIV transmission through oral sex are low; a UCSF study put the risk at 4 cases out of every 10,000.
There are other STIs that can be transmitted through oral sex as well. Chlamydia, syphilis, and gonorrhea can all take root in the throat. Gonorrhea is the most common; antibiotic resistant cases are on the rise and difficult to treat. Chlamydia and syphilis are less common but still transmittable.
Herpes and HPV can also be transmitted through oral sex. HPV, in particular, is something to watch out for. It can be transmitted through skin-to-skin contact; in other words, you don't need a cut or a sore in your mouth for it to infect you. Getting HPV through oral sex will increase your risk of developing mouth or throat cancer. Herpes is transmittable through oral sex as well; you're at highest risk when sores are present, although transmission is still possible when they aren't.
The person who's giving the oral sex - that's the partner with the genitals in their mouth - is at higher risk of catching an STI. They're exposed to the bulk of potentially infectious fluids. Giving cunnilingus, broadly speaking, is less risky than giving a blowjob.
If you're not sure that you or your partner are STI-free, you may want to abstain from sex (including oral sex). You can also try oral sex with prophylactics such as lubricated condoms or a dental dam.
Possible short-term side effects
- sexually transmitted infections