First time sex: a guide to staying safe

There’s no set time when you should have sex for the first time. What matters is that you both want to, and that you both feel safe and respected. Before you go ahead, it can help to ask yourself:

• Do I want to do this, or do I feel under pressure from my partner or friends?
• Do I trust this person and feel safe with them?
• Have we talked about condoms and contraception?
• Would I be OK saying no or stopping if I changed my mind?

Consent means both of you agree to sex, freely and every time. You can stop at any point, even once you have started. In the UK, the age of consent is 16, whatever your gender or sexuality.

If you’re not sure about your answers, it’s fine to wait. Many people feel more relaxed when they take things slowly.

Yes. You can catch an STI the first time you have sex, and you can also get pregnant. STIs don’t only spread through vaginal or anal sex. Some pass on through oral sex, close genital contact or sharing sex toys.

Many STIs cause no symptoms, so your partner may have an infection without knowing. Someone who has never had vaginal or anal sex can still have an STI, for example genital Herpes caught through oral sex from a partner with a cold sore. Read more in “Can virgins have STIs?”

Using a condom from the very start, and getting tested if you’re worried, are the best ways to protect yourself.

Condoms are the only type of contraception that helps protect against both pregnancy and STIs. They are the best way to protect yourself and your partner from HIV and other STIs during vaginal, anal and oral sex.

• Condoms are up to 98% effective at preventing pregnancy if you use them correctly every time. In typical use, when mistakes happen, they are around 82% effective.
• Internal condoms, sometimes called female condoms, are worn inside the vagina or anus. They are up to 95% effective at preventing pregnancy if you use them correctly every time, and around 79% effective in typical use.
• Put the condom on before there is any contact between the penis and your partner’s genitals, mouth or anus, and use a new one each time you have sex.
• For oral sex on a vagina or anus, use a dental dam.
• Don’t use oil-based lubricant with latex condoms. Use a water-based or silicone-based one instead.

Condoms don’t cover all the skin around the genitals. This means they can’t fully protect you from STIs that spread through skin contact, such as Herpes, HPV and Syphilis, and they won’t stop pubic lice or scabies. Read more in “3 STIs you can catch even if you use a condom”

Other types of contraception prevent pregnancy, but they don’t protect you from STIs. Many people use one of these as well as condoms:

• The pill: over 99% effective if you always take it correctly, but around 91% in typical use, when pills get missed.
• The contraceptive injection: lasts 8 to 13 weeks, depending on the type.
• The contraceptive implant: a small rod put under the skin of your upper arm that lasts up to 5 years.
• The contraceptive patch: you change it once a week for 3 weeks, then usually have a week without one.
• The vaginal ring: you leave it in for 3 weeks, then usually have a week without one.
• The copper coil (IUD): lasts 5 or 10 years, depending on the type.
• The hormonal coil (IUS): lasts 3 to 8 years, depending on the type.

A doctor or nurse can help you choose the method that suits you. Read more in “Contraception: preventing STIs and choosing the right contraception for you”

If a condom breaks or comes off, or you had sex without contraception, emergency contraception can help prevent pregnancy. There are two types:

• the copper coil (IUD), which can be fitted up to 5 days after sex and is the most effective type
• the emergency contraceptive pill, which you take within 3 days (levonorgestrel) or 5 days (ulipristal acetate) after sex

The emergency pill works better the sooner you take it, and you can get it from most pharmacies. It doesn’t protect you from STIs, so think about getting tested too. Read more in “My condom broke. What should I do now? First steps and when to test”

The World Health Organization estimates there were 374 million new cases of Chlamydia, Gonorrhoea, Syphilis and Trichomonas worldwide in 2020, among people aged 15 to 49. Here are some STIs that are useful to know about.

Chlamydia

Chlamydia is the most commonly diagnosed STI in England, with 151,163 diagnoses in 2025. Most people who have it get no symptoms. It is treated with antibiotics, but if it isn’t treated, it can cause pelvic inflammatory disease (PID), an infection of the womb, fallopian tubes and ovaries.

Gonorrhoea

Gonorrhoea can infect the genitals, bottom and throat, and many people don’t notice any symptoms. It is getting harder to treat. In England, cases resistant to ceftriaxone, the main antibiotic used for it, rose from 13 in 2024 to 29 in 2025, and 21 more were reported in 2026 by the end of August. Most cases still respond to treatment.

Syphilis

Syphilis usually starts with a small, painless sore on the genitals, around the bottom or in the mouth, which you might not notice. It spreads through contact with the sore during sex. It is treated with antibiotics, most often a penicillin injection. Early Syphilis usually needs just one injection, but if you have had it longer you may need more, and you’ll have follow-up blood tests to check the treatment has worked.

Genital Herpes

Herpes spreads through skin contact, even when there are no sores. The virus that causes cold sores (HSV-1) can spread to the genitals during oral sex, and it is now the most common cause of genital Herpes in the UK. There’s no cure, but antiviral medicine can help control outbreaks.

HIV

With treatment, most people with HIV live a long and healthy life. Someone on effective treatment with an undetectable viral load can’t pass HIV on. A medicine called PrEP can help protect people at higher risk from getting HIV, but it doesn’t protect against other STIs.

HPV

HPV is very common, and most people will get some type of it in their life. Some types cause genital warts, and others can lead to cancer. The HPV vaccine is offered to all children aged 12 to 13. If you missed it, girls can still have it up to their 25th birthday, and so can boys born after 1 September 2006. Men aged 45 or under who have sex with men can also get it through sexual health and HIV clinics.

Trichomonas

Trichomonas is more common in women than men, and many people have no symptoms. It is treated with antibiotics, usually metronidazole. If you have it while pregnant, it can cause your baby to be born early or with a low birthweight.

Sex shouldn’t hurt, although it might feel a bit strange at first. If it is painful, it may be a sign that you’re not turned on enough or you’re feeling nervous. Taking your time, going gently and using a water-based lubricant can all help. You can stop at any point.

If sex is painful, especially if it keeps happening, see a doctor. Pain can be a sign of an STI, thrush, a urine infection, or vaginismus, which is when the vagina suddenly tightens when you try to put something into it.

You may have heard that the hymen breaks the first time you have vaginal sex. The hymen is a thin, stretchy ring of skin around part of the opening of the vagina, not a seal, and some people are born without one. Some people bleed a little the first time and some don’t. There’s no way to tell from someone’s body whether they have had sex.

Get tested straight away if you notice any symptoms, such as unusual discharge, pain when peeing, or sores, blisters or lumps around your genitals, mouth or anus. If you don’t have symptoms, some infections need time to show up on a test:

• Chlamydia and Gonorrhoea: from about 2 weeks after sex.
• HIV: UK guidance says a fourth-generation lab blood test is reliable from 45 days after sex, and a rapid finger-prick test that gives an instant result from 90 days.
• Syphilis: a test in the first 3 months can miss it, so you may need a repeat test.

If you think you have been exposed to HIV, get urgent medical care straight away and ask about PEP (post-exposure prophylaxis), a medicine that can stop you getting HIV. It has to be started within 72 hours, and the sooner you start it, the better.

Better2Know offers:

• Full Screen: tests for Chlamydia, Gonorrhoea, Hepatitis B, HIV, Mycoplasma, Syphilis and Ureaplasma, from 28 days after sex, with results in 3 days. You can book it at one of our clinics or order a Full Screen home test.
• Peace of Mind: tests for Chlamydia, Gonorrhoea and Syphilis from 14 days, with results in 2 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.

If you test before the window periods above, you may need a repeat test for HIV or Syphilis later. Not sure which test you need? Our Patient Care Team is available 24/7 on 020 7099 0955. Read more in “Should we get tested before having sex? How to talk to a new partner”

Can you get pregnant the first time you have sex?

Yes. You can get pregnant the first time you have vaginal sex, so use contraception from the start if you don’t want to get pregnant.

Do you need a condom if you’re both virgins?

It’s still a good idea. Some STIs can be caught through oral sex, genital contact or from birth, so a partner who has never had penetrative sex can still have one without knowing. A condom also helps prevent pregnancy.

Is it normal to bleed the first time?

Some people bleed a little the first time they have vaginal sex and some don’t. Both are normal. If you have heavy bleeding, or you bleed after sex again later on, see a doctor. Bleeding after sex can be a sign of an STI such as Chlamydia, so it’s a good idea to get tested too.

Your first time should be your choice, with someone you trust. Talk about condoms and contraception before you have sex, take things slowly, and remember you can stop at any point.

You can catch an STI the first time you have sex, and many STIs cause no symptoms. If you’re worried, get tested. Book a Full Screen at a clinic near you or order a home test kit. 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 22 August 2025 and was last updated on 29 September 2026.

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

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