How long after a cold sore can you give oral sex?

Don’t give oral sex until your cold sore has completely healed. Cold sores are contagious from the moment you first feel tingling until the sore has fully healed, and giving oral sex before then could give your partner genital Herpes.

After the blisters burst, they crust over into a scab. The scab is still part of the cold sore, so wait until it has gone and the skin has healed.

Even after a cold sore has healed, there is still a small chance of passing on the virus, because it can be present on skin that looks normal. The risk is highest when there is a sore. Once it has fully healed, using a condom or dental dam for oral sex lowers the risk further.

Cold sores are caused by the Herpes simplex virus, usually Herpes simplex virus type 1 (HSV-1). They are sometimes called fever blisters.

Once you have the virus, it stays in your body for life, resting in a cluster of nerve cells near the face. From time to time it can become active again and cause a new cold sore. Common triggers include being ill, strong sunlight, periods and stress.

A cold sore usually starts with a tingling, burning or itching feeling. Over the next 48 hours, small fluid-filled blisters appear, which then burst and crust over into a scab.

Most cold sores clear up on their own within about 10 days. A first ever outbreak can take longer, sometimes 2 to 3 weeks, and can come with a fever, aches and swollen glands. Later outbreaks are usually shorter and milder.

Antiviral cold sore creams, such as aciclovir, are sold in pharmacies. They work best if you use them as soon as you feel the first tingle, and they can help the sore heal faster. But they don’t make it safe to give oral sex before the cold sore has healed.

See a doctor if a cold sore hasn’t started to heal within 10 days, it’s very large or painful, you keep getting cold sores, you also have swollen, painful gums and sores in your mouth, or you have a weakened immune system, for example because of chemotherapy or diabetes. Read more in “I got Herpes. How can I treat my cold sores?”

The virus that causes cold sores spreads through close contact, such as kissing, touching a cold sore, and oral sex. It can also spread to other parts of your body, so wash your hands with soap and water whenever you touch your cold sore.

People with HSV-1 often have the virus in their mouth without any sore or symptoms. This is called asymptomatic shedding. Studies suggest it happens on roughly 5 to 10 days in every 100, so Herpes can be passed on even when the skin looks normal. The risk is still highest when there is a sore.

Yes. If you give oral sex while you have a cold sore, you could give your partner genital Herpes. HSV-1, the virus behind most cold sores, is now the most common cause of genital Herpes in the UK. Sexual health services in England diagnosed 28,779 first episodes of genital Herpes in 2025.

Genital Herpes caused by HSV-1 tends to come back less often than genital Herpes caused by Herpes simplex virus type 2 (HSV-2). After a first outbreak, HSV-2 typically comes back about 4 times a year, while genital HSV-1 comes back much less often. For most people, outbreaks become less frequent over time.

HSV-2 can occasionally infect the mouth through oral sex, but this is uncommon and it rarely causes repeat cold sores. Read more in “Oral vs genital Herpes: what is the difference?”

UK sexual health guidance says someone who already has the same type of Herpes isn’t expected to catch it again. So if your partner already has HSV-1, the risk of passing it on to them is low.

But this isn’t a total guarantee. Catching a second strain of the same type has been reported, although it is rare. Your partner having HSV-1 also doesn’t protect them from HSV-2. And most people don’t know for sure which type of Herpes they or their partner have, because many people with Herpes have no symptoms, and blood tests can miss HSV-1.

The safest approach is still to avoid kissing and oral sex from the first tingle until your cold sore has fully healed.

You can lower the risk of passing on Herpes by:

• not kissing anyone or giving oral sex from the first tingle until your cold sore has completely healed
• not touching your cold sore, and washing your hands with soap and water if you do
• once your cold sore has fully healed, using a condom for oral sex on a penis, or a dental dam for oral sex on a vagina or anus, which lowers the risk but doesn’t remove it
• never kissing a baby while you have a cold sore, because Herpes can be very dangerous for newborns

UK guidance also advises anyone who gets cold sores to avoid kissing newborn babies in their first 4 to 6 weeks.

If your partner is pregnant, take extra care. UK guidance advises pregnant people who don’t get cold sores to avoid receiving oral sex in the last 3 months of pregnancy, and the 2 weeks before that, even if their partner has no cold sore at the time. Catching Herpes for the first time late in pregnancy can be very dangerous for the baby.

If you have genital Herpes caused by HSV-2, taking antiviral tablets every day roughly halves the risk of passing it on to a partner. This hasn’t been studied for HSV-1. Read more in “Do condoms protect against Herpes?”

The best test for Herpes is a swab taken from a sore. Take it as soon as possible, before the sore scabs over, as the test is less likely to find the virus once a sore starts to heal.

• Herpes Simplex Type 1 and 2 (Swab): tests a swab from a sore on or around your mouth or genitals for Herpes 1 and Herpes 2, with results in 5 days.
• Blemish Screen: if you have a sore, blister or lump on or around your genitals, it tests a swab for Herpes 1, Herpes 2, HPV and Syphilis.
• Herpes Simplex Type 1 and 2 (IgG): a blood test that can show whether you have had HSV-1 or HSV-2 in the past.

A blood test can take several weeks to turn positive after infection, so you may need a repeat test 12 weeks after you think you caught it. It also can’t tell you where on your body the infection is or when you caught it. UK guidelines see blood tests as useful in certain situations, rather than as a routine check for people without symptoms.

Not sure which test you need? Our Patient Care Team is available 24/7 on 020 7099 0955.

Can you give oral sex when a cold sore is just tingling?

No. Cold sores are contagious from the first tingle, before any blister appears, so wait until the cold sore has completely healed.

Can you get a cold sore from receiving oral sex?

Receiving oral sex exposes your genitals, not your mouth, so the risk is genital Herpes if your partner has the virus in their mouth. You can get HSV-1 in your mouth by giving oral sex to someone with genital HSV-1, although if you already have HSV-1, you aren’t expected to catch it again.

How common is the cold sore virus?

Very common. The World Health Organization estimates that about 3.8 billion people under 50, around 2 in 3, have HSV-1. Most people with Herpes don’t know they have it.

Wait until your cold sore has completely healed, including the scab stage, before you give oral sex. Most cold sores heal within about 10 days. Giving oral sex with a cold sore can pass on Herpes to your partner’s genitals, and even after healing, a condom or dental dam lowers the risk further.

If you or your partner has a sore you’re worried about, get tested. Book a Herpes Simplex Type 1 and 2 (Swab) test at a clinic near you. Our Patient Care Team is available 24/7 on 020 7099 0955.

Not in the UK? Choose your country from the selector at the top of the page for local tests and prices.

This article originally appeared on 28 April 2023 and was last updated on 29 September 2026.

Medical review. This article was medically reviewed by Dr Steve Chapman, Doctor with a wealth of clinical experience in the field of STIs, on 29 August 2025. It is general information and not a substitute for personal medical advice.

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