Can you still get an STI if you wear a condom?

Yes, although it’s much less likely. The NHS says using a condom every time you have sex is the best way to protect you and your partner from HIV and other STIs. Condoms stop semen, vaginal fluid and blood passing between partners, which protects well against infections spread in these fluids, such as HIV, Chlamydia and Gonorrhoea.

But condoms only cover the penis, or line the vagina or anus. Some STIs spread through skin-to-skin contact, and condoms only work if they’re used correctly from start to finish.

These infections can pass on from skin a condom doesn’t cover:

• Herpes can pass on from the first tingle of an outbreak until the sores have healed, and sometimes when there are no symptoms at all. In one study, condoms cut the chance of passing Herpes from men to women by 96% each time a couple had sex, and from women to men by about 65%.
• HPV, which causes genital warts, spreads through skin contact in the genital area, even when there are no warts.
• Syphilis spreads through contact with a sore, which can be on the genitals, around the bottom or in the mouth.
• Pubic lice and scabies spread through close body contact. The NHS says condoms won’t protect you from pubic lice.
• Mpox spreads through close contact with its rash, blisters or scabs. The World Health Organization says condoms reduce the risk but won’t stop skin-to-skin spread.

Read more in “3 STIs you can catch even if you use a condom”

Condoms are up to 98% effective at preventing pregnancy when used correctly every time, but only 82% effective if they’re not used correctly. The same mistakes that cause pregnancies can let STIs through:

• putting the condom on after sex has started
• not squeezing the air out of the tip
• using the wrong size
• using oil-based lube, such as Vaseline, with latex condoms
• using 2 condoms at once, which makes them more likely to split
• using a condom that’s damaged or past its use-by date
• taking it off too soon, or not holding the base when pulling out

If a condom splits or comes off and there was a risk of HIV, PEP (emergency HIV medicine) needs to be started within 72 hours, so get urgent medical care straight away. You may also need emergency contraception. Read more in “Can condoms fail without breaking?”

Oral sex can pass on Herpes, Gonorrhoea, Chlamydia, Syphilis and HPV. The NHS suggests using a condom to cover the penis, or a latex or plastic square called a dental dam to cover the vagina, if you have oral sex.

Brook says dental dams might offer some protection, but there’s very little research on how well they work. You can make one from a condom by cutting off the tip and the ring, then cutting along its length. Read more in “I had unprotected oral sex. Should I get tested?”

No. Only barrier methods, such as condoms, protect against STIs. The NHS says the combined pill and the IUD (coil) don’t stop you getting or passing on STIs.

• Internal condoms, sometimes called female condoms, go inside the vagina or anus. They protect against STIs during vaginal sex, but there isn’t enough evidence to say how well they protect during anal sex.
• Dental dams are for oral sex on the vulva or anus. They aren’t contraception.

If you use the pill or a coil, you still need condoms to protect against STIs.

Condoms work best alongside other protection:

• PrEP is HIV medicine. Taken daily and correctly, it’s around 99% effective at preventing HIV. It doesn’t protect against other STIs.
• The HPV vaccine protects against the types of HPV that cause most genital warts and cervical cancers. It’s offered to all children aged 12 to 13, and to some adults, including gay, bisexual and other men who have sex with men up to the age of 45.
• The Hepatitis B vaccine is recommended for people at higher risk, including people who change sexual partners often.
• The mpox vaccine, and the MenB vaccine, which gives some protection against Gonorrhoea, are offered to people at higher risk, mainly men who have sex with men.

The MenB vaccine gives around 30% to 40% protection against Gonorrhoea, and the NHS says you should keep using condoms after having it.

Many STIs have no symptoms, so testing is the only way to know. UK guidelines suggest testing:

• at least once a year if you’re sexually active, and when you change partner
• every 3 months if you’re at higher risk, for example if you have several partners or take PrEP
• at the start of a new relationship
• after a condom splits, slips off or isn’t used

Get tested straight away if you notice symptoms, such as unusual discharge, pain when you pee, or a sore, blister or lump on your genitals.

Better2Know offers:

• Platinum Screen: tests for 12 infections, including Herpes 1, Herpes 2, Syphilis, HIV, Chlamydia and Gonorrhoea, from 28 days after sex, with results in 3 days.
• Full Screen: tests for 7 infections, including HIV, Syphilis, Chlamydia and Gonorrhoea, from 28 days after sex, with results in 3 days (5 days for the home test).
• 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, with results in 5 days.

If you test before 45 days, a negative HIV result needs a repeat test. A Syphilis test in the first 3 months after sex can miss the infection, so you may need a repeat test. A Herpes blood test can also miss a recent infection, so you may need to test again later. Not sure which test you need? Our Patient Care Team is available 24/7 on 020 7099 0955.

Do condoms protect against Herpes?

They lower the risk, but they don’t remove it, because Herpes can pass on from skin the condom doesn’t cover. Avoid sex from the first tingle of an outbreak until the sores have healed.

Can you get Chlamydia if you use a condom?

It’s much less likely, as Chlamydia spreads in semen and vaginal fluid. But it can pass on if the condom splits, slips off or goes on after sex has started, or during oral sex without a condom.

Are two condoms safer than one?

No. The NHS says using more than one condom can make one or both split. Use one condom, with a water-based or silicone-based lube if you need it.

Condoms are still the best everyday protection against STIs, but they can’t cover everything. Use them correctly every time, add a condom or dental dam for oral sex, and think about vaccines and PrEP if they’re right for you. Regular testing helps catch infections a condom misses.

Book a Platinum Screen 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 8 September 2023 and was last updated on 1 October 2026.

This article is general information and not a substitute for personal medical advice.

Sources

1. NHS, Condoms, reviewed 26 January 2024. https://www.nhs.uk/contraception/methods-of-contraception/condoms/
2. NHS, Internal (female) condoms, reviewed 15 February 2024. https://www.nhs.uk/contraception/methods-of-contraception/internal-condoms/
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19. Brook, Condoms, updated 1 July 2026. https://www.brook.org.uk/your-life/condoms/
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21. Brook, Dental dams, updated July 2024. https://www.brook.org.uk/your-life/dental-dams/
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25. World Health Organization, Mpox, 26 August 2024. https://www.who.int/news-room/fact-sheets/detail/mpox