Can you get an STI from blowjobs? – Risks of oral sex

Many people consider oral sex to be a safer form of sexual activity—after all, it does not involve traditional penetration. But is that really true? Can sexually transmitted infections (STIs) also be transmitted through oral sex?
In this article, you will learn how high the actual risk is, which infections can be transmitted, what symptoms may occur, and how you can effectively protect yourself.

Table of Contents

• What is oral sex?
• Can you get an STI from oral sex?
• Which STIs can be transmitted through oral sex?
• Symptoms: How STIs can appear in the mouth or throat
• How can you protect yourself during oral sex?
• What should you do after unprotected oral sex?

What is oral sex?

Oral sex refers to sexual practices in which the mouth, lips, or tongue come into contact with another person’s genitals or anus. This includes:

• Blowjobs: Oral stimulation of the penis

• Cunnilingus: Oral stimulation of the vulva or vagina

• Anilingus: Oral stimulation of the anus (“rimming”)

Even though oral sex does not involve penetrative intercourse, infectious agents can still be transmitted through mucous membranes, bodily fluids, or small injuries in the mouth (CDC, 2024). 

Can you get an STI from oral sex?

In short: Yes – but the risk is generally lower than with vaginal or anal sex.

During oral sex, pathogens present in semen, vaginal fluids, urine, blood, or on mucous membranes can be transmitted. Whether the performing or receiving partner becomes infected depends on exposure to infectious material.

Factors that increase the risk:

• Wounds, ulcers, or bleeding gums in the mouth

• A high pathogen load in the infected partner

• Inflammation or other STIs that make the mucous membranes more vulnerable

• Lack of protection (no condom or dental dam)

• Oral sex during menstruation (blood contact)

The risk of infection depends on several factors – but in general: With protective measures and regular testing, the risk can be significantly reduced.

Source: Cleveland Clinic, 2023

Which STIs can be transmitted through oral sex?

Several sexually transmitted infections can be passed on during oral sex. The likelihood varies depending on the pathogen and the type of contact:

Sources: Cleveland Clinic, 2023, Mayo Clinic, 2024, CDC,2024

Note:
The risk of HIV transmission through oral sex is very low, especially if there is no blood involved and no open wounds in the mouth.
According to the CDC and WHO, the risk is considered “low to negligible.”

Symptoms: How STIs can appear in the mouth or throat

Many infections are completely asymptomatic – especially throat infections, which are often discovered only by chance during testing.
Nevertheless, the following signs may occur:

Common symptoms in the mouth and throat:

• Sore throat or difficulty swallowing

• Redness, small blisters, or white patches in the throat

• Swollen lymph nodes in the neck

• Burning or pain when swallowing

• Ulcers, blisters, or warts in the mouth

• Bad breath or an unpleasant taste

General STI symptoms (depending on the pathogen):

• Unusual discharge from the penis, vagina, or anus

• Itching or burning in the genital area

• Pain when urinating

• Skin rashes or fever

If you notice any of these symptoms – especially after unprotected oral sex – you should get tested (Mayo Clinic, 2024).

How can you protect yourself during oral sex?

The risk of transmission can be significantly reduced if you follow these precautions:

1. Use condoms and dental dams

• For oral sex on the penis: Use condoms (latex or polyurethane)

• For oral sex on the vulva or anus: Use a dental dam

• Ensure that the condom fits properly, is not damaged, and is not reused

• Avoid condoms with sugar- or oil-based lubricants, as they can damage latex

2. Maintain good oral hygiene

• Avoid oral sex if you have open sores, ulcers, or bleeding gums

• After dental treatments or cleanings, it’s best to wait a few days

• Maintain good oral hygiene and use alcohol-free mouthwash

3. Communicate and build trust

• Talk openly with your partner about STI status and recent tests

• Regular testing provides reassurance and safety for both partners

4. Get vaccinated

• Vaccination against Hepatitis B and HPV can help protect against infection

Source: NHS, 2024

What should you do after unprotected oral sex?

If you’ve had unprotected oral sex and are unsure:

1. Watch for symptoms over the following weeks

2. Get tested after about 2–3 weeks, even if you have no symptoms

3. Repeat the test after the recommended window period (e.g., HIV after 6 weeks, syphilis after 3–12 weeks)

4. If you experience symptoms or unusual results: Seek medical advice and get treatment

Source: Mayo Clinic, 2024 

Which tests are useful?

Depending on the type of contact, different tests may be appropriate:

Homed-IQ Tip

With the Chlamydia & Gonorrhoea Test from Homed-IQ you can easily test yourself for these two bacteria from the comfort of your home – using a urine sample, vaginal swab, or swab from the throat or rectum.