When should I test for STIs?
STIs don't show in a test straight away. There's a period of time between getting the infection and when it will show up in a test.
So you need to wait a few weeks after sexual contact before a test will be accurate. This time is called the window period. And window periods are different for different infections.
We recommend waiting for the end of the window period before taking your samples and sending them to us. If a test is done inside the window period, it can be too soon to spot an infection that's in the early stages and not yet visible in tests.
How long does it take for STIs to show in tests?
These are the window periods for the at-home tests we use.
Chlamydia: 2 weeks
Gonorrhoea: 2 weeks
HIV: 7 weeks
Hepatitis B: 12 weeks
Hepatitis C: 12 weeks
Syphilis: 12 weeks
Hepatitis C can sometimes take up to 9 months to show in a test, so if you're not sure when you might have been exposed, do a test now, and another test in 9 months.
If you may have been exposed to HIV in the last 72 hours (3 days), you should find out if you can take PEP (Post-Exposure Prophylaxis) to reduce your risk.
How often should I test for STIs?
We recommend testing for STIs:
every 3 months if you regularly have sex with different people
each year if you’re sexually active but do not change partners often
If you’re in a long-term, monogamous relationship, you do not need to test as often.
These recommendations follow national guidelines set by BASHH (British Association for Sexual Health and HIV).
In some cases you might want to test again before 3 months have passed. We recommend you contact your local sexual health clinic for STI testing in these cases, including when:
you’ve been told that a recent sexual partner has an STI and you need to test - in these cases you can get rapid testing and treatment in a clinic.
you have symptoms of an STI - it’s always recommended to visit a clinic if you have symptoms. At-home test kits are more suitable for regular check ups when you do not have any symptoms.
If you need to test more frequently than our service allows, your clinic can help you with personalised advice and support, including information on when to test, safer sex practices and explaining the clinical science behind your results.
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