Which STIs/STDs can you get from oral sex?

Megan Alphabiolabs

By Megan Souness, Technical Manager for Health Testing and Covid‑19 at AlphaBiolabs
Last reviewed: 24/11/2023

In this guide, we discuss the sexually transmitted infections (STIs) that can be passed on during oral sex, how you can reduce your risk of catching an STI/STD from oral sex, and how to get tested for STIs
Table of contents
  • What is a sexually transmitted infection (STI)?
  • What is oral sex?
  • Can you catch an STI during oral sex?
  • How are STIs/STDs passed on through oral sex?
  • Which STIs can you catch from having oral sex?
  • What can increase your chances of getting an STI during oral sex?
  • Is oral sex safer than penetrative sex (vaginal/anal sex)?
  • How can I reduce the risk of catching an STI from oral sex?
  • How can I get tested for an STI from oral sex?

What is a sexually transmitted infection (STI)?

A sexually transmitted infection (STI) – sometimes referred to as a sexually transmitted disease (STD) – is an infection that is most commonly passed on during sexual activity, especially if unprotected.

This can include infections that are transmitted via skin-to-skin contact, sexual touching, or via oral, vaginal, or anal sex. Some STIs can even be passed on to unborn babies during pregnancy and childbirth.

What is oral sex?

Oral sex, sometimes called oral intercourse, is a type of sexual activity where a person uses their mouth and tongue to stimulate the genitals or genital area of their sexual partner.

There are different forms of oral sex including fellatio (involving the penis), cunnilingus (involving the vagina), and anilingus (involving the anus).

Can you catch an STI during oral sex?

Many STIs are passed on through skin-to-skin contact and bodily fluids, including semen and vaginal fluids, meaning that it is entirely possible to catch an STI/STD during oral sex.

Oral sex involves using your mouth to stimulate your partner’s genitals or genital area.

This means that if you or your partner have an STI and participate in oral sex, there’s a high chance you could end up catching it or passing the infection on.

It is possible to get an STI/STD in the mouth, throat, genitals, or rectum by having oral sex with an infected person.

How are STIs/STDs passed on through oral sex?

Many STIs are spread through bodily fluids and skin-to-skin contact.

This means that if you have oral sex (give or receive) there is a high risk of you catching an STI from an infected person or passing on an infection to your partner.

How the infection spreads depends entirely on the type of infection you have:

  • Some STIs/STDs can be spread to the mouth or throat from oral sex
  • If a person has a mouth or throat infection, this infection can be spread to their partner’s genitals or genital area following oral sex
  • Some STIs transmitted from oral sex can spread to other parts of the body (e.g. syphilis and gonorrhoea)
  • Hepatitis A and hepatitis B can be passed on during oral sex involving the anus (anilingus)

Which STIs can you catch from having oral sex?

It is possible to catch the following STIs/STDs by having oral sex with a person who has an infection:

Chlamydia

Chlamydia is a bacterial infection caused by Chlamydia trachomatis that is usually spread via sexual contact and genital fluids (semen or vaginal fluid).

It is especially common among sexually active teenagers and young adults. Symptoms can include pain when urinating and unusual discharge.

Chlamydia can infect the throat, genitals, rectum, and urinary tract.

Gonorrhoea

Gonorrhoea is an infection caused by Neisseria gonorrhoeae or gonococcus bacteria and passed on through sexual activity, including oral sex.

The infection is mainly found in discharge from the penis and in vaginal fluid. Symptoms can include a thick green or yellow discharge, pain when urinating and, in women, bleeding between periods.

Gonorrhoea can infect the throat, genitals, rectum, and urinary tract.

Syphilis

Syphilis is an infection caused by Treponema pallidum (T. pallidum) bacteria.

It develops in four stages and, depending on the stage of the infection, symptoms can include painless, firm, round sores on the genitals or other parts of the body, a red or red-brown rash, muscle aches, swollen lymph nodes, headaches, sore throat, and fatigue.

Syphilis can infect the lips, mouth, throat, genitals, anus, and rectum.

Herpes

Herpes is an infection that is typically passed on through oral, vaginal, or anal sex.

There are two types of herpes infection, both of which are caused by the herpes simplex virus: HSV-1, which typically causes oral herpes (cold sores) but can also cause genital herpes, and HSV-2, the more common cause of genital herpes.

Herpes can infect the lips, mouth, throat, genitals, anus, rectum, and buttocks.

HIV

Human Immunodeficiency Virus (HIV) is a virus that is transferred through bodily fluids including vaginal fluids, semen, and blood. The virus weakens the immune system over time. Early symptoms can include fever, headaches, tiredness/fatigue, loss of appetite, a sore throat and/or swollen lymph nodes.

Thanks to advances in medical science including early detection using laboratory testing, and treatment for HIV using retroviral drugs, it is now possible to stop the virus from replicating in the body, allowing the immune system to repair itself, and ensuring the virus remains undetectable.

When HIV is undetectable, the virus cannot be passed on to other people, even while it remains in the body. This means you can have sex – including oral sex – without passing the virus onto your partner. This is known as undetectable = untransmittable (U=U).

You can read more about U=U and treatment options at www.sexwise.org.uk.

Human papillomavirus (HPV)

HPV is the name for a group of common viruses that can be spread via skin-to-skin contact of the genitals, and oral, vaginal, and anal sex.

Most of the time HPV does not cause any symptoms, but it can cause genital warts in some people, or abnormal changes in the cells that are linked to certain cancers, including cervical cancer.

Oral HPV is a common STI, infecting the mouth and throat.  However HPV can also infect the genitals, cervix, anus, and rectum.

Hepatitis A, Hepatitis B and Hepatitis C

Hepatitis is a term that describes the inflammation of the liver, usually because of a viral infection.

There are several types of hepatitis including hepatitis A, which is caused by a virus that is spread in faeces (poo), hepatitis B, which is spread via bodily fluids such as blood, vaginal fluid, and semen, and hepatitis C, which is usually spread via blood. Each of these forms of hepatitis can be spread during sexual contact – including oral sex – with an infected person.

Symptoms of hepatitis can include muscle and joint pain, a high temperature, fatigue, loss of appetite, itchy skin, and jaundice.

If you are experiencing symptoms that are causing you severe pain and discomfort, or that require in-person examination, we advise you to contact your GP or local sexual health clinic as soon as possible.

For further guidance, visit www.sexwise.org.uk.

What can increase your chances of getting an STI during oral sex?

Many STIs/STDs are passed on through skin-to-skin contact and bodily fluids, meaning that you are at an increased risk of catching an STI if you have unprotected sex.

Although oral sex is thought to be lower risk than penetrative (vaginal, anal) sex, this does not mean that oral sex is risk-free.

Factors that can increase your risk of getting an STI during oral sex include:

  • You and/or your partner have unprotected oral sex with multiple partners
  • You and/or your partner engage in drug use before/during oral sex – this is sometimes referred to as ‘chemsex’
  • Sharing sex toys that have not been cleaned between uses
  • You or your partner have cuts or sores around your mouth, genitals, or anus. Infections can travel more easily through broken skin

You can reduce the risk of catching STIs by using protection each time you have oral sex (e.g. condoms, dental dams or other barrier methods), and by getting tested regularly for STIs.

For further guidance, visit www.sexwise.org.uk.

Is oral sex safer than penetrative sex (vaginal/anal sex)?

The risk posed by different types of sex (oral, vaginal, anal) depends on several factors, including how sexually active a person is, how many sexual partners they have, what protection is used during sexual activity, how often they get tested for STIs and, if they have an infection, the type of infection they have.

The important thing to remember is that, because many STIs are spread via skin-to-skin contact or bodily fluids (semen, vaginal fluids), oral sex is not risk-free.

Many types of STIs can be passed on during oral sex, including some of the most common infections such as chlamydia, gonorrhoea, syphilis, and herpes.

How can I reduce the risk of catching an STI from oral sex?

You can reduce the risk of catching STIs by using protection each time you have oral sex (e.g. condoms, dental dams or other barrier methods).

This can help prevent skin-to-skin contact and the spread of bodily fluids, which can cause infections.

Regular sexual health checks, including testing for some of the most common and often symptomless infections can also help reduce the risk of catching STIs and spreading them to other people.

Other ways to reduce the risk of catching an STI from oral sex can be found at https://www.sexwise.org.uk/stis/oral-sex-and-sexually-transmitted-infections

How can I get tested for an STI from oral sex?

Whether you are experiencing symptoms that indicate you could have an STI, or do not have symptoms and just want a test to put your mind at rest, an at-home STI test from AlphaBiolabs is a simple, discreet and confidential way of finding out whether you have contracted an infection.

Your test kit will contain everything you need to collect your samples and return them to our UK laboratory.

However, if you are experiencing symptoms that are causing you severe pain and discomfort, or that require in-person examination, we advise you to contact your GP or local sexual health clinic as soon as possible.  They will be able to provide advice on next steps for testing, diagnosis, and treatment.

Order an STI test kit

At-home STI testing you can trust, from just £29.

Megan Souness

Megan Souness

Technical Manager for Health Testing at AlphaBiolabs

Megan joined AlphaBiolabs in 2020 and holds the role of Technical Manager, playing a fundamental part in the research and development of the company’s new health testing services.

She also oversees the day-to-day processes in the Health Laboratory, managing the in-house validation and training of all new workflows, and ensuring the lab operates to the highest possible quality and technical standards.

During her time at AlphaBiolabs, Megan has played a key role in the development and launch of the company’s health testing services, including the introduction of a full suite of at-home STI tests, and the progression of the laboratory to ISO 15189 accreditation.

Megan holds a BSc in Biochemistry, an MSc in Biological Sciences, and is a member of the British Association for Sexual Health and HIV (BASHH).

Related articles…

Can you catch an STI/STD with a condom?

How condoms can help prevent the spread of sexually transmitted infections (STIs) and when to use them to reduce the risk of infection.

Everything you need to know about Herpes

This guide contains everything you need to know about herpes including what it is, the signs and symptoms of the infection, how it’s treated, and how often you should get tested.

Everything you need to know about chlamydia

This guide contains everything you need to know about chlamydia including what it is, signs and symptoms of the infection, how it’s treated, and how often you should get tested.