What is PrEP?

PrEP—or "Pre-Exposure Prophylaxis"—is a safe and effective way for HIV-negative people to prevent HIV by taking medication before and after sex. 

Currently only one medication has been researched and proven to be effective as PrEP. That medication is marketed under the brand name Truvada. Many people in Europe are using generic versions of PrEP which are sold under different names but contains the same active ingredients—emtricitabine and tenofovir disoproxil. Generic PrEP is just as safe and effective as brand-name Truvada.

Does PrEP really work?

Yes. PrEP is proven to be safe and highly effective for HIV prevention. 

The World Health Organization recommends that it be available to anyone at substantial risk for HIV. That might include gay and bisexual men, trans people who have sex with men, people with a sexual partner with HIV who has been on effective treatment for less than 6 months, as well as other people who are concerned about reducing their risk of contracting HIV.

PrEP works for men and women, both cis and trans people. Some dosing regimens (ways of taking PrEP) are suitable for everyone, others should be used only if you're having anal sex but not vaginal sex. 

How does PrEP work?

PrEP works by preventing HIV from replicating inside your body. If you’re taking PrEP correctly and are exposed to HIV, there will be enough drug present to prevent HIV from being able to establish an infection. 

How safe is PrEP?

PrEP is very safe. One of the reasons that Truvada was chosen for PrEP is that it has few side effects. Truvada has been used as HIV treatment for more than 15 years and the potential side effects are well understood. The PrEP protocol includes tests specifically to catch any occurrence of any serious side effects.

About 10% of people who use Truvada as PrEP experience some initial side effects—stomach pain, back aches, diarrhoea—but these typically disappear within a few days or weeks. If you experience prolonged or especially severe side effects, you should talk to a doctor. You might also find it helpful to talk to other people who may have had similar experiences in a forum like the PrEP Fact Facebook group.

A very small number of people experience changes to their kidney function. Although this is rare, it’s one of the reasons it’s important to take PrEP only with proper medical support to monitor for these rare but potentially serious side effects.

PrEP can be safely used during pregnancy as well as with hormone therapy.

What about condoms?

By itself, PrEP provides powerful protection against HIV. That makes it a great HIV prevention option for people who don't always use condoms. But PrEP doesn't provide protection against other STIs.

Condoms offer good protection against other STIs, and there's no reason you can't use PrEP and condoms together. Many PrEP users continue to use condoms to reduce their risk of contracting other STIs. In addition, the regular STI testing that's part of the PrEP programme means that if you do contract an STI—including through oral sex—it will be diagnosed and treated quickly. 

PrEP isn't meant to replace condoms, it just adds another option to the growing range of tools we have to prevent HIV transmission. Using PrEP doesn't mean you have to stop using condoms, it just means you don't have to worry about HIV if you do.

Want to know more?

If you'd like to learn more about PrEP, please see the links on our Resources page. You can also ask a question or leave a comment on our Contact page.