Oral Sex: What It Is, Health Risks and How to Stay Safe

Many people think of oral sex as “safe sex” because it cannot cause pregnancy. But safe sex means sex that lowers the risk of sexually transmitted infections (STIs), and oral sex can still pass on several of them. This guide explains what oral sex is, which infections it can spread, the symptoms to watch for and how to protect yourself and your partner.

What is oral sex?

Oral sex is sexual activity where one person uses their mouth, lips or tongue to stimulate a partner’s genitals or anus. It includes mouth-to-penis, mouth-to-vagina and mouth-to-anus contact.

It is common among adults and is often seen as lower risk than vaginal or anal sex. That is partly true for some infections, such as HIV, but not for others.

Is oral sex safe?

Oral sex is not risk-free. Infections pass through contact with semen, vaginal fluid, blood, or skin and sores in the genital, anal or mouth area. The risk is higher when either partner has:

• Cuts, sores or ulcers in the mouth or on the genitals
• Bleeding gums or recent dental work
• A sore throat or throat infection
• An untreated STI, even one without symptoms

Oral sex is lowest risk between two partners who have both tested negative for STIs and only have sex with each other.

Health risks of oral sex: infections it can spread

Gonorrhoea. Can infect the throat as well as the genitals. Throat gonorrhoea often causes no symptoms, so it can be passed on without either partner knowing. Read what you should know about gonorrhoea.

Chlamydia. Can also infect the throat, usually without symptoms.

Syphilis. Spreads through direct contact with a syphilis sore, which can appear on the lips, mouth, genitals or anus. Untreated syphilis can damage the heart, brain and other organs over time.

Herpes. The cold sore virus (HSV-1) can be passed from the mouth to the genitals during oral sex, and genital herpes can pass to the mouth.

HPV (human papillomavirus). Some types of HPV spread through oral sex and can cause cancers of the throat, base of the tongue and tonsils. HPV vaccination lowers this risk.

HIV. The chance of getting HIV from oral sex is much lower than from vaginal or anal sex, but it is not zero, especially when there are sores, bleeding gums or ejaculation in the mouth.

Hepatitis A and B, and gut infections. Mouth-to-anus contact can spread hepatitis A, and bacteria and parasites such as E. coli and shigella.

Symptoms of an STI from oral sex

Many oral STIs cause no symptoms at all, which is why testing matters. When symptoms do appear, they can include:

• A sore throat that does not go away
• Redness or white spots at the back of the throat, similar to tonsillitis
• Sores, blisters or ulcers on the lips, mouth or tongue
• Swollen glands in the neck
• Unusual discharge, burning when urinating, or sores on the genitals or anus

If you notice any of these after oral sex, see a doctor. Do not self-treat with antibiotics from a chemist. The wrong drug or dose can leave the infection untreated and add to antibiotic resistance.

How to reduce your risk

• Use a barrier every time. Use a condom for oral sex on a penis. For oral sex on a vagina or anus, use a dental dam (a thin latex or polyurethane sheet) or a condom cut open into a square. Use one male condom at a time; never use a male and female condom together.
• Get tested regularly. Ask for throat swabs as well as genital tests if you have oral sex. Both partners should test before stopping barrier use.
• Avoid oral sex when there are sores. Wait if either partner has a cold sore, mouth ulcer, genital sore or bleeding gums.
• Look after your mouth. Good oral hygiene lowers the chance of cuts and sores. Avoid brushing or flossing just before oral sex, as it can cause small cuts in the gums.
• Get vaccinated. Ask your doctor about HPV and hepatitis B vaccines.
• Limit your number of partners and talk openly about sexual health and testing before sex.

For more on separating facts from myths, read 7 most common sex myths, busted.

Frequently asked questions

Can you get pregnant from oral sex?
No. Pregnancy needs sperm to reach the vagina. But oral sex can still spread infections.

Can you get HIV from oral sex?
The risk is low but possible, especially with mouth sores, bleeding gums or ejaculation in the mouth. Barriers and regular testing reduce it further.

Can oral sex cause throat cancer?
Some types of HPV passed on through oral sex can cause throat cancer years later. HPV vaccination and fewer partners lower the risk.

How soon should I test after unprotected oral sex?
Many STIs show up on tests from about 2 weeks after exposure, but some, such as syphilis and HIV, can take longer. A doctor can advise on timing and whether you need a repeat test.

Does Reliance HMO cover STI tests and treatment?
Reliance HMO members can speak to a doctor privately on the Reliance Care app and see a doctor at partner hospitals. Download it for iPhone or Android. Some STI tests, such as syphilis and chlamydia screening, may not be covered on every plan, so check your plan’s benefits and exclusions or ask us before you test.

Planning ahead? Private STI tests and consultations are easier with health cover. See what an HMO is and how it works.

This article is for general information and does not replace advice from your doctor.

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