More information about PrEP and how it works is provided below.

What is PrEP?


Pre-Exposure Prophylaxis (PrEP) is an HIV prevention strategy that uses antiretroviral drugs to lower HIV-negative persons’ risk of HIV-infection. PrEP is best used in an HIV combination prevention strategy, comprising medical, as well as behavioural measures (eg. condom use). PrEP can be used in several ways: vaginal gel, vaginal ring, rectal gel or oral tablets. At this moment, only the oral tablet (pill) ‘Truvada’ is approved for use by the US Food and Drugs Administration, which consists of two different antiretroviral drugs (Emtricitabine and Tenofovir). The oral tablet is generally preferred because its efficacy has been clearly demonstrated in clinical studies. Furthermore, it has limited side effects and has few problems with drug resistance (that an HIV-virus would develop in such a way that certain antiretroviral drugs are no longer effective). Moreover, it reaches high levels in the genital tract and rectum and remains in the body for a relatively long time, what makes this drug very effective.

How does PrEP work?


When the HIV-virus enters the body, it needs certain cells to replicate. PrEP prevents that the HIV-virus would enter those cells and would replicate. This prevents HIV from establishing itself in the body.

Is PrEP always effective?


Research has shown that PrEP is highly effective among men and transgender persons who have sex with men (MSM). For PrEP to be highly effective, adherence is very important: the tablets need to be taken correctly, without missing any dose. It is assumed that PrEP is as effective as a condom against HIV infection.

Can you still get HIV when you are taking PrEP?


PrEP’s protective effect is highly dependant on the user’s individual behavior. Research has shown that the more correctly pills are taken, the lower the chances of HIV-infection. PrEP is not able to offer 100% protection, as any other prevention measure, and therefore it is recommended to use condoms as well.

Does PrEP also prevent other sexually transmitted infections (STIs)?


PrEP is only effective in preventing HIV-infection, not other STIs (such as gonorrhea, syphilis or hepatitis C). Therefore, it remains highly important that condoms are still being used, while using PrEP.

When taking PrEP I can have sex without a condom, with everyone?


PrEP offers protection against HIV-infection for HIV-negative persons. It is intended to protect those having condomless sex, having sex with multiple partners who are HIV-positive or whose HIV-status is unknown to them. However, PrEP’s purpose is not to stimulate people in having more sex, using less condoms or having sex with more partners. Because PrEP does not offer protection against other STIs, condoms need to be used as well.

How do you take PrEP?


In general, there are two possible regimen: daily and event-driven. With daily PrEP the intention is that you take one tablet, every day. Event-driven PrEP means that you would have to take a double dose (two tablets) of PrEP 2-24h before having sex; after sex one has to take two separate doses for two consecutive days.

For whom?


PrEP is intended for HIV-negative persons who are at high risk of HIV-infection. PrEP can be used by IV drug users, people (homo- or heterosexual) who have a lot of variable sex partners or who frequently have sex without a condom. It is important to note that PrEP is not a substitute for condoms.

Side effects?


As in other retroviral products, PrEP (Truvada) can have several side effects on short term, such as nausea, fatigue, gastro-intestinal symptoms and headache. These side effects generally occur in one out of ten people, in the first week of use. Moreover, in people with reduced kidney function and bone mineral density one needs to be cautious.

Available in Belgium?


Would you like more information on how and where you can get PrEP? Please, see this page.