I had sex with a sex worker. Which STI test is right for me?

If you had any sex without a condom, or the condom broke or slipped off, it’s a good idea to get tested. The same applies after sex without a condom with any new partner.

Many sex workers use condoms with clients and have regular sexual health check-ups. In the UK, HIV is uncommon among sex workers overall, although HIV and some other STIs are more common in some groups. What matters most for your risk is the kind of sex you had and whether you used a condom.

Many STIs, including Chlamydia and Gonorrhoea, often cause no symptoms, so you can’t tell from how you feel. Testing is the only way to know.

Your risk of catching an STI depends on:

• the kind of sex you had: for HIV, anal sex carries the highest risk, followed by vaginal sex, while the risk from oral sex is very low
• whether you used a condom the whole time, and whether it broke or came off
• whether your partner has an infection, which you usually can’t know
• how many partners you’ve had

Oral sex is more often done without a condom, and it can still pass on Gonorrhoea, Chlamydia, Syphilis and Herpes. Read more in “I had unprotected oral sex. Should I get tested?”

If you think a partner injects drugs, tell whoever tests you, as they may suggest extra tests, such as for Hepatitis B and C.

A condom that splits or slips off counts as sex without a condom.

If it happened in the last 72 hours, get urgent medical care straight away and ask about PEP (post-exposure prophylaxis). PEP is a 28-day course of medicine that can stop you getting HIV. It works best the sooner you start it, ideally within 24 hours, and it isn’t recommended after 72 hours. A doctor will check whether you need it, as it is mainly given after higher risk sex, such as receptive anal sex, or when a partner is known to have HIV and isn’t on effective treatment.

If you haven’t been vaccinated against Hepatitis B, ask about a fast course of the vaccine. Read more in “What is PEP and how does it work?”

A good STI check after sex with a new partner usually includes:

• Chlamydia and Gonorrhoea
• Syphilis
• HIV
• Hepatitis B, especially if you haven’t been vaccinated

If you have symptoms, or a partner tells you they have an infection, it can also be worth testing for Trichomonas, Mycoplasma and Herpes.

If you gave oral sex or were the receiving partner in anal sex, ask for throat or rectal swabs as well as a urine test, because a urine test won’t pick up infections in your throat or bottom.

You can get tested straight away, but some infections take time to show up on a test:

• Chlamydia and Gonorrhoea: from about 2 weeks after sex.
• HIV: a fourth-generation lab blood test is reliable from 45 days, and a rapid or self-test from 90 days.
• Syphilis: a test in the first 3 months can miss it, so test again 3 months after sex.
• Hepatitis B, Hepatitis C and Herpes: these can take several weeks or months to show up on a blood test, so you may need a repeat test.

Some tests can pick up HIV from 10 days after sex, but a negative result that early doesn’t rule HIV out, so you’ll need a follow-up test at 45 days.

If you notice sores, blisters, unusual discharge or pain when you pee, see a doctor and get tested straight away rather than waiting. Syphilis sores are usually painless, so get any sore checked.

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 (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.
• Platinum Screen: our most comprehensive STI screen. It tests for 12 infections, adding Hepatitis C, Herpes 1, Herpes 2, Trichomonas and Gardnerella to the Full Screen, from 28 days after sex, with results in 3 days.
• Confidence Screen: the Full Screen plus throat and rectal swabs for Chlamydia and Gonorrhoea, with results in 5 days. It is designed for gay and bisexual men.
• Oral Screen home test: if you gave oral sex. It checks your throat and genitals for Chlamydia and Gonorrhoea, and tests your blood for Syphilis, Herpes 1 and Herpes 2, from 14 days (28 days for Herpes).
• Early Platinum Screen: tests for the same 12 infections as the Platinum Screen from 14 days after sex, with results in 3 days. Some infections, such as HIV and Syphilis, can be missed this early, so if your results are negative you’ll need follow-up tests.
• Early Detection Screen: tests for HIV, Hepatitis B and Hepatitis C from 10 days after sex, with results in 3 days. A negative HIV result at this stage needs a follow-up test at 45 days, and you may need repeat tests for Hepatitis B and C.

Not sure which test you need? Our Patient Care Team is available 24/7 on 020 7099 0955. Read more in “Which STI test do I need? How to choose the right test after a new partner”

You can lower your risk by:

• using a condom for vaginal, anal and oral sex, and checking it stays on
• getting vaccinated against Hepatitis B, which is recommended for anyone who changes sexual partners often
• taking PrEP if you are at higher risk of HIV
• getting tested every 3 months if you have several partners, and after sex without a condom with a new partner

Is sex with a sex worker high risk?

Not necessarily. In the UK, HIV is uncommon among sex workers overall, and many use condoms and test regularly. But HIV and some other STIs are more common in some groups of sex workers, and any sex without a condom with a new partner carries a risk. The kind of sex you had and whether you used a condom matter most.

Should I tell the clinic I paid for sex?

You don’t have to, but it helps to say what kind of sex you had and whether you used a condom, so you’re offered the right tests, such as throat or rectal swabs. Better2Know testing is confidential.

Should I get tested if I don’t have symptoms?

Yes. Many STIs, such as Chlamydia, often cause no symptoms, so it’s worth testing after any risk, even if you feel fine.

Sex with a sex worker doesn’t automatically mean you’ve caught an STI, but any sex without a condom with a new partner is a good reason to get tested. If a condom wasn’t used or it broke in the last 72 hours, get urgent medical care and ask about PEP.

Many STIs cause no symptoms, so test at the right time. 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 4 March 2013 and was last updated on 30 September 2026.

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

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