Home STI tests: how they work and what to expect

How often should I get STI tested?

Sexual contact between two people can sometimes result in the spread of infections. These are known as sexually transmitted infections, or STIs, and getting an early diagnosis can be the difference between full recovery and serious, long-term health issues.

There are many types of STIs, including chlamydia, gonorrhoea, HIV (human immunodeficiency virus), and syphilis. These are usually spread through vaginal, anal and oral sex.

Here are some key times to get yourself tested:

• If you have a symptom that you think is due to an STI - but remember many STIs can be symptomless.

• After a high-risk encounter - such as unprotected sex with a new sexual partner, or with someone you don't know is STI-free. Remember, condoms protect against STIs as well as pregnancy.

• Ideally, it's best to get tested before you have sex with someone for the first time.

• If you regularly have sex with different people, then healthcare experts recommend getting tested once every one to three months.

Can you get an STI test at home?

You can be tested for STIs at your local sexual health clinic - a GUM (genitourinary medicine) clinic specialises in this. However, you may feel more comfortable ordering a home STI test.

Benefits of home testing include:

• The comfort and convenience of testing in your own home.

• Privacy and by-passing difficult conversations - some people may prefer not to discuss this directly with a professional.

Are STI home tests accurate?

The National Institute for Health and Care Research (NIHR) has analysed a range of studies and concluded that taking a home STI test or having one carried out by a clinician should make no difference to the accuracy of your results².

No STI test is 100% reliable, whether completed by yourself or a healthcare professional. Most tests are considered clinically reliable if they have a 90% accuracy rating².

Here are some tips for improving the reliability of your home STI test:

• Test after your incubation period - this refers to the time period that you can have an STI before your body produces virus-fighting antibodies, and it's these that indicate a positive test result. The incubation period depends on the type of STI you have.

• Speak to a sexual health expert if you're unsure which STIs to test for based on your symptoms and/or your sexual history, and for the relevant incubation period.

• Follow your home STI test kit instructions carefully.

Where can I get a home STI test?

STI testing kits are now widely available to order from online sexual health services - in the UK high street pharmacies like Superdrug and Boots offer a wide range of test kits. These include tests for specific STIs, such as HIV tests, or package kits that test for the most common STIs in one go.

You may be able to obtain a free NHS home STI test kit - criteria and availability will depend on your local NHS district. Likewise, sexual health charities such as Brook provide some free kits. Again, you'll need to check which ones are available in your local area.

Patient picks for Sexually transmitted infections

Sexual health

How good is PEP for preventing HIV?

These days, we all know that HIV isn't a death sentence. Thanks to modern medicine, people with HIV can live long, healthy and thoroughly normal lives - something that only a few decades ago would have been the stuff of miracles. All this said, if you think you may have been exposed to HIV, it's understandable that you'd be worried. Don't panic - if you deal with the situation promptly there's a reliable way to reduce your risk: post-exposure prophylaxis (PEP).

by Abi Millar

Sexual health

Trichomoniasis

Trichomoniasis is a sexually transmitted infection (STI) caused by a tiny germ called trichomonas vaginalis. It can lead to pain and discharge from the vagina or penis, but it often does not cause any symptoms. This means you can pass it on without knowing you have it.

by Dr Rachel Hudson, MRCGP

How to do an STI test at home

Although the exact steps can vary slightly between the type of STI you're testing for and the testing service you use, a home STI test is typically convenient, easy, and quick.

Usual steps

1. Order your home STI test kit online.

2. Receive your kit in the post or choose to pick up from a local collection point.

3. Take your samples - finger prick, swab, urine sample, or combination (see Types of STI samples following).

4. Post your samples to the laboratory for analysis - a freepost envelope for Royal Mail or private courier should be provided.

5. Get your test results - depending on the company, this could be by text, email, or another preferred method.

6. If your test results indicate you have an STI, book in for treatment - some sexual health services automatically send your results to your GP.

Types of STI samples

The kind of sample you need to collect will depend on what you're being tested for:

• Finger prick blood sample home STI test - checks for HIV and syphilis.

• Urine sample home STI test - checks for chlamydia and gonorrhoea.

• Swab home STI test - either involves rubbing a cotton bud in the vaginal region (females only), rectal region (males only), or throat. This also tests for chlamydia and gonorrhoea.

If you're testing for multiple STIs in one test kit, you'll be instructed to carry out a combination of the above. All sample types are relatively straight-forward and quick to complete - your test provider will send clear step-by-step instructions.

How long before an STI shows up on a test?

Some STIs can take anywhere between a few weeks or months to show a positive test result. Speak to a healthcare professional if you're unsure when to test to avoid the incubation period.

Once you've decided when to take your home STI test, it usually only takes 2-5 working days to arrive, and a matter of minutes or even seconds to complete. The time it takes for you to receive your test results depends on the company you choose. Some are relayed as early as one working day after the lab receives, but anywhere between 5-10 working days³is normal.

Further reading

1. GOV.UK: Gonorrhoea and syphilis at record levels in 2022.

2. National Institute for Health and Care Excellence: Self-testing kit for sexually transmitted infections increases diagnoses while reducing costs.

3. Sexual Health Hub: At home STI tests.