Does peeing after sex really prevent STIs?

No. There’s no good evidence that peeing after sex lowers the risk of catching an STI. The NHS, the World Health Organization and the US Centers for Disease Control and Prevention (CDC) don’t mention it in their advice on preventing STIs.

STIs can infect the vagina, cervix, penis, bottom, mouth and throat, and some, like Herpes and HPV, are passed on through skin contact rather than body fluids. Peeing afterwards doesn’t undo any of that.

Washing after sex doesn’t protect you either. The CDC says washing or douching after sex doesn’t protect against STIs or HIV, and may raise the risk of bacterial vaginosis (BV), some STIs and HIV.

According to the NHS, STIs are passed on through:

• vaginal, anal or oral sex without a condom
• skin-to-skin contact of the genital area, which can pass on Herpes, HPV and Trichomonas, and Syphilis through contact with a sore
• sharing sex toys
• blood, for example by sharing needles to inject drugs, which can pass on HIV, Hepatitis B, Hepatitis C and Syphilis
• pregnancy and birth, which can pass several STIs on to a baby, including HIV, Syphilis, Hepatitis B and Trichomonas

Many STIs have no symptoms, so you can have one without knowing and pass it on. In the UK, donated blood is tested for infections, so the risk from a blood transfusion is very low. Read more in “7 ways you can catch an STI without having sex”

It may help. UTIs are usually caused by bacteria from poo getting into the urinary tract, and sex can move bacteria from the bottom towards the urethra (the tube you pee through). Women have a shorter urethra than men, so bacteria reach the bladder more easily.

The NHS advises peeing as soon as possible after sex to lower your risk. But the evidence is weak: NICE, which writes guidance for the NHS, says its advice on hygiene measures like this is based on its committee’s experience. It’s still an easy habit, and it does no harm.

Other NHS tips to lower your risk of a UTI:

• wipe from front to back after going to the toilet
• drink plenty of fluids, particularly water, so you pee regularly during the day
• wash the skin around the vagina with water before and after sex
• keep your genital area clean and dry, and don’t use scented soap on it
• don’t hold your pee in when you need to go
• don’t use condoms, diaphragms or caps with spermicidal lube on them

Read more in “Is a UTI caused by sex?”

A UTI isn’t an STI, and you can’t pass one to a partner. But sex can trigger a UTI, and some STIs, like Chlamydia, Gonorrhoea, Trichomonas and Mycoplasma genitalium, can cause pain or burning when you pee, just like a UTI.

The NHS lists these UTI symptoms:

• pain or a burning feeling when you pee
• needing to pee more often, or more suddenly, than usual
• cloudy pee, or blood in your pee
• pain in your lower tummy, or in your back just under the ribs

It’s worth testing for STIs too if your symptoms started after sex with a new partner, a urine test for a UTI comes back clear, you keep getting “UTIs”, or you also have unusual discharge. In men, burning when you pee is often caused by an STI. Read more in “Is a UTI an STI?”

Get urgent medical care if:

• you have a very high or low temperature, or feel hot and cold or shivery
• you have pain in your lower tummy, or in your back just under the ribs
• you have blood in your pee
• you’re pregnant, 65 or older, or have diabetes or a weakened immune system
• you’re a man with UTI symptoms
• you keep getting UTIs
• your symptoms get worse quickly, or don’t improve within 2 days of treatment

In an emergency, call 999, including if you feel confused or drowsy, or find it hard to speak.

These are the things that do lower your risk of an STI:

• Using condoms for vaginal and anal sex, and condoms or dental dams for oral sex. They don’t cover all the skin around the genitals, so they don’t fully protect against HPV or Herpes.
• Not sharing sex toys, or washing them and putting a new condom on them each time.
• Taking PrEP if you’re at higher risk of HIV, and PEP within 72 hours if you might have been exposed to HIV.
• Vaccines: the HPV and Hepatitis B vaccines, the Hepatitis A vaccine for some groups, and the MenB vaccine, which is offered to some gay and bisexual men in England to help protect against Gonorrhoea.
• Testing regularly, and after a new partner, because many STIs have no symptoms.

Read more in “Why you should never reuse a condom”

Better2Know offers:

• Full Screen: tests for 7 infections, including Chlamydia, Gonorrhoea, HIV, Syphilis and Hepatitis B, from 28 days after sex, with results in 3 days (5 days for the home test). If you test before 45 days, a negative HIV result needs a repeat test. You can book it at one of our clinics or order a Full Screen home test.
• Comfort Screen: if it burns or stings when you pee, it tests a urine sample for 8 infections that can cause genital symptoms, including Chlamydia, Gonorrhoea, Trichomonas and Mycoplasma, from 14 days after sex, with results in 2 days.
• Urine Analysis: Culture and Microscopy: checks your pee for a UTI and which antibiotics will work against it, with results in 2 days.

The Full Screen includes a Syphilis test. A Syphilis test in the first 3 months after sex can miss the infection, so you may need a repeat test. Not sure which test you need? Our Patient Care Team is available 24/7 on 020 7099 0955.

Should I pee after sex?

If you get UTIs, it’s worth doing, and the NHS recommends it. It won’t protect you from STIs, though.

Can a UTI turn into an STI?

No. A UTI isn’t an STI and can’t become one. But some STIs cause similar symptoms, so if you’re not sure what’s causing them, test for both.

Does washing after sex prevent STIs?

No. Washing or douching after sex doesn’t protect against STIs or HIV, and douching can upset the balance of bacteria in the vagina.

Peeing after sex is a sensible habit if you get UTIs, but it won’t stop you catching an STI. Condoms, vaccines and regular testing are what protect you, and a test is the only way to know if you have an STI.

Book a Full Screen at a clinic near you or order a home test kit from 28 days after sex. 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 was last updated on 30 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 April 2025. It is general information and not a substitute for personal medical advice.

Sources

1. NHS, Urinary tract infections (UTIs), reviewed 11 July 2025. https://www.nhs.uk/conditions/urinary-tract-infections-utis/
2. NICE, Urinary tract infection (recurrent): antimicrobial prescribing (NG112), 2018, updated May 2025. https://www.nice.org.uk/guidance/ng112/chapter/Summary-of-the-evidence
3. UK Health Security Agency, Diagnosis of urinary tract infections: quick reference tools for primary care, updated 7 July 2025. https://www.gov.uk/government/publications/urinary-tract-infection-diagnosis/diagnosis-of-urinary-tract-infections-quick-reference-tools-for-primary-care
4. Brook, Cystitis, updated 24 September 2026. https://www.brook.org.uk/your-life/cystitis/
5. NHS, Kidney infection, reviewed 13 February 2025. https://www.nhs.uk/conditions/kidney-infection/
6. NHS, Urethritis, reviewed 10 May 2023. https://www.nhs.uk/conditions/urethritis/
7. NHS, Sexually transmitted infections (STIs), reviewed 13 May 2024. https://www.nhs.uk/conditions/sexually-transmitted-infections-stis/
8. NHS, Chlamydia, reviewed 24 October 2024. https://www.nhs.uk/conditions/chlamydia/
9. NHS, Gonorrhoea, reviewed 16 December 2024. https://www.nhs.uk/conditions/gonorrhoea/
10. NHS, Trichomoniasis, reviewed 16 July 2025. https://www.nhs.uk/conditions/trichomoniasis/
11. NHS, Genital herpes, reviewed 27 June 2023. https://www.nhs.uk/conditions/genital-herpes/
12. NHS, Human papillomavirus (HPV), reviewed 10 March 2026. https://www.nhs.uk/conditions/human-papilloma-virus-hpv/
13. NHS, Syphilis, reviewed 17 March 2026. https://www.nhs.uk/conditions/syphilis/
14. NHS, HIV and AIDS, reviewed 9 July 2025. https://www.nhs.uk/conditions/hiv-and-aids/
15. NHS, Hepatitis B, reviewed 17 November 2025. https://www.nhs.uk/conditions/hepatitis-b/
16. NHS, Hepatitis C, reviewed 19 March 2026. https://www.nhs.uk/conditions/hepatitis-c/
17. NHS, Hepatitis A, reviewed 24 April 2026. https://www.nhs.uk/conditions/hepatitis-a/
18. NHS, Blood transfusion, reviewed 16 January 2025. https://www.nhs.uk/conditions/blood-transfusion/
19. UK Health Security Agency, 4CMenB vaccine for gonorrhoea: information for healthcare practitioners, published 8 July 2025. https://www.gov.uk/government/publications/4cmenb-vaccine-for-gonorrhoea-information-for-healthcare-practitioners
20. Centers for Disease Control and Prevention, Primary prevention methods, reviewed 3 June 2024. https://www.cdc.gov/std/treatment-guidelines/clinical-primary.htm
21. World Health Organization, Sexually transmitted infections (STIs), 10 September 2025. https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis)
22. British HIV Association, British Association for Sexual Health and HIV and British Infection Association, Adult HIV testing guidelines, 2020. https://bhiva.org/wp-content/uploads/2024/10/HIV-testing-guidelines-2020.pdf
23. British Association for Sexual Health and HIV, UK guidelines for the management of syphilis, 2024. https://bashh.org/_userfiles/pages/files/syphilis_2024.pdf