References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
Several STIs can be transmitted through oral sex, including gonorrhoea, herpes, syphilis, chlamydia, and HPV. The risk varies by infection and by the type of oral sex (giving vs receiving, and which body parts are involved). Oral sex is generally lower risk than vaginal or anal sex for most STIs, but it’s not risk-free.
This guide covers which infections can be transmitted orally, what the symptoms look like, and how to get tested in the UK. If you’re experiencing a sore throat, mouth sores, or other symptoms after oral sex, this is for you.
Get tested with a discreet home STI test kit — includes throat swab
Which STIs Can You Get from Oral Sex?
Not every STI transmits easily through oral sex. Here’s the evidence-based breakdown:
| STI | Oral Transmission Risk | Most Common Route | Symptoms in Mouth/Throat | Testable? |
|---|---|---|---|---|
| Gonorrhoea | Moderate-high | Giving oral to infected genitals | Sore throat, redness, swollen glands (often none) | Yes — throat swab |
| Herpes (HSV-1/2) | Moderate-high | Contact with active sore or viral shedding | Cold sores, blisters on lips/gums | Yes — swab during outbreak, blood test |
| Syphilis | Moderate | Contact with a chancre (sore) | Painless sore on lip/tongue/throat, mucous patches | Yes — blood test |
| Chlamydia | Low-moderate | Giving oral to infected genitals | Usually none; mild sore throat rarely | Yes — throat swab |
| HPV | Moderate | Oral contact with infected genital skin | Warts (rare); long-term throat cancer risk | No routine oral test |
| HIV | Very low | Exposure to blood or semen via mouth wounds | None specific to oral route | Yes — blood test |
| Hepatitis A | Low (oral-anal contact) | Rimming (mouth to anus) | Nausea, jaundice (systemic, not oral) | Yes — blood test |
Chlamydia and Oral Sex
Chlamydia can infect the throat, though it’s less efficient at spreading orally than genitally. The risk is highest when giving oral sex to someone with genital chlamydia.
Throat chlamydia usually causes no symptoms. When it does, you might notice a mild sore throat. Most cases are only detected through screening. A standard urine chlamydia test will not detect throat infection. You need a specific throat swab.
Treatment is the same as genital chlamydia: a course of doxycycline or azithromycin. Read more: Oral chlamydia explained
Gonorrhoea and Oral Sex
Pharyngeal (throat) gonorrhoea is more common than many people realise, and oral sex is the primary way it’s transmitted. BASHH guidance notes that throat gonorrhoea is frequently asymptomatic and often only discovered during routine screening.
When symptoms do appear, they typically include a sore throat, difficulty swallowing, and swollen neck glands. These can easily be mistaken for a regular throat infection. The key difference: throat gonorrhoea won’t respond to standard cold and flu remedies, and it won’t go away on its own.
Treatment requires an antibiotic injection (ceftriaxone), usually combined with oral azithromycin. This is different from genital gonorrhoea treatment because throat infections can be harder to clear.
Herpes (HSV-1 and HSV-2)
Oral herpes (usually HSV-1) is extremely common, and most people contract it in childhood from non-sexual contact. However, both HSV-1 and HSV-2 can be transmitted during oral sex in either direction:
- A cold sore on the mouth can transmit HSV-1 to a partner’s genitals during oral sex
- Genital herpes (HSV-2) can be transmitted to a partner’s mouth during oral sex, though this is less common
- Transmission can happen even without visible sores (asymptomatic viral shedding)
Symptoms of oral herpes include tingling, blisters, and cold sores on or around the lips. Antiviral medication like aciclovir or valtrex can manage outbreaks.
Syphilis
Syphilis can be transmitted through oral sex if the mouth comes into contact with a syphilis sore (chancre). These sores can appear on the genitals, anus, lips, or inside the mouth. They’re often painless and can be easy to miss.
A primary syphilis chancre in the mouth looks like a single, firm, round sore on the lip, tongue, or inner cheek. It heals on its own within weeks, but the infection remains and progresses to secondary syphilis without treatment.
Syphilis is curable with penicillin injections at any stage. Early detection makes treatment simpler. Read more: What is syphilis?
HPV and Throat Cancer Risk
HPV (human papillomavirus) can be transmitted to the mouth and throat during oral sex. Most oral HPV infections clear on their own within 1-2 years. However, certain high-risk HPV strains (particularly HPV-16) are linked to oropharyngeal cancer, which affects the back of the throat, tonsils, and base of the tongue.
According to Cancer Research UK, HPV causes around 70% of oropharyngeal cancers in the UK. This cancer type has increased in recent decades, likely due to changes in sexual behaviour.
There is no routine test for oral HPV. The HPV vaccine (offered to all children aged 12-13 in the UK) protects against the highest-risk strains and should reduce oropharyngeal cancer rates over time.
Persistent symptoms to watch for: a lump in the throat or neck, difficulty swallowing, earache on one side, or a hoarse voice lasting more than 3 weeks. See your GP if you have any of these.
How to Reduce the Risk
- Condoms for oral sex on men — flavoured condoms are designed for this purpose
- Dental dams for oral sex on women — a thin latex or polyurethane sheet placed over the vulva
- Avoid oral sex during outbreaks — if you or your partner has visible cold sores, herpes blisters, or syphilis sores
- HPV vaccination — protects against the highest-risk strains
- Regular testing — especially if you have new or multiple partners
- Hepatitis A vaccination — recommended for men who have sex with men and anyone practising oral-anal contact
Many people don’t use barrier protection for oral sex. If that includes you, regular STI screening with throat swabs becomes particularly important.
How to Get Tested for Oral STIs
If you’re concerned about an STI from oral sex, the testing process is straightforward:
- Throat swab — tests for gonorrhoea and chlamydia. Quick, painless, results in 1-3 days
- Blood test — tests for syphilis, HIV, herpes antibodies, and hepatitis
- Visual examination — a clinician can identify herpes sores, syphilis chancres, or warts
You can get tested at a sexual health clinic (free, no GP referral needed) or order a home test kit that includes a throat swab option. Make sure to mention oral sex exposure when requesting tests, as throat swabs are not always included in a standard screen unless you ask.
Frequently Asked Questions
Is giving or receiving oral sex riskier?
Giving oral sex (mouth on genitals) carries more risk for the person using their mouth, as the throat is exposed to genital fluids and skin. Receiving oral sex carries lower risk but isn’t zero, as the genitals are exposed to the partner’s saliva and any oral infections they may have.
Can you get HIV from oral sex?
The risk is very low but not zero. HIV transmission through oral sex would require the virus (in semen, vaginal fluid, or blood) to enter the bloodstream through a cut, sore, or damaged tissue in the mouth. Using a condom or dental dam eliminates this risk.
Can you get an STI from kissing?
Herpes (HSV-1) can be transmitted through kissing. Syphilis can be transmitted if a sore is present in or around the mouth. Chlamydia, gonorrhoea, HIV, and HPV are not transmitted through kissing alone.
I gave oral sex and now have a sore throat. Should I be worried?
A sore throat after oral sex can be caused by physical irritation rather than infection. However, if it lasts more than 2 weeks, doesn’t respond to normal remedies, or is accompanied by swollen glands, get a throat swab test for gonorrhoea and chlamydia.
Do I need to tell my dentist about oral STIs?
Your dentist may notice signs of oral herpes, syphilis, or HPV-related changes during a routine check-up. Being open about your sexual health history helps them provide better care. All healthcare consultations are confidential.
Related reading
- Blood Test for Syphilis, Hepatitis B and Hepatitis C
- Can You Get an STI From Being Fingered?
- Can You Catch an STI From a Toilet Seat?
- Can You Clear HPV Once You Have It?
- Can You Die From Hepatitis B?
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
