HIV Testing Week: Why do I need to get tested for HIV before taking PrEP?

HIV Testing Week: Why do I need to get tested for HIV before taking PrEP?

Ant Gifford

February 2, 2024

Next week is the 10th National HIV Testing Week, and across the UK sexual health groups will be running events and campaigns to highlight the importance of regular HIV testing. But why is getting tested for HIV so important, especially before starting on pre-exposure prophylaxis (PrEP)?

People can live with HIV for a long time before symptoms show

It is super important to know your HIV status, as many people who contract HIV can go for a long time before experiencing any symptoms. If you do test positive for HIV, then you can start antiretroviral medication right away, which stops you getting symptoms and can reduce the amount of virus in your body (the ‘viral load’) meaning you can’t pass it to other people. If you get tested regularly, and start treatment early then you can live with HIV.

I tested negative for HIV at my last test, why do I need to test again before taking PrEP?

It can take up to 3 months after being exposed before most tests can accurately detect a HIV infection. As such, if you have casual sex or have recently changed partners, it is always a good idea to get tested for HIV at least every 3 months.

It’s also essential to know you are HIV negative before you start taking PrEP, which can then prevent you from getting HIV. PrEP is highly effective at preventing HIV infection but it’s not effective for people that already have HIV.

Learn more about what PrEP is»

PrEP uses a lower dose of the same drugs that are used to treat people with HIV. This is enough to prevent someone who is HIV negative from getting HIV but not enough to control HIV in someone who already has it.

If someone who has HIV starts taking PrEP, the drug won’t be strong enough to stop the HIV virus, but it does give the virus an opportunity to adapt to resist the treatment. If this happens often enough it could lead to new forms of HIV that cannot be effectively treated and that aren’t stopped by PrEP either. For this reason, whether you are accessing PrEP through a sexual health provider or self-sourcing, it is essential that you ensure you do not have HIV before starting a PrEP regime.

Learn more about different types of HIV»

How can I get tested?

Although National HIV testing week offers many opportunities to get tested, you can get tested at any time, and you can even get tested at home. HIV tests are available as postal test kits delivered to your door or you can go to your local sexual health clinic. Follow the link below to the Terrence Higgins Trust website which can help you learn where and how you can get tested:

For more information about PrEP and support for how to start PrEP and ensure you’re always protected, download the free, safe and secure Preptrack app.