The Lesbian & Gay Foundation, together with community based HIV prevention agencies from across England, have developed a joint statement on Pre – Exposure Prophylaxis.

What is PrEP?

Pre-Exposure Prophylaxis (PrEP) is a promising new way of preventing HIV infections. PrEP involves people who do not have HIV taking a daily dose of one or two of the drugs that are used to treat HIV. Studies suggest that this can prevent infection if the user is exposed to HIV.1

At present in the UK PrEP is only available to participants in a clinical trial (the PROUD study - see below)

Why do we need PrEP?

It is now over 30 years since the first AIDS case was identified in the UK. In that time, over 50,000 gay men have been diagnosed with HIV.2

Tens of thousands of HIV transmissions have been prevented by condom use.3 However, for a wide variety of reasons, many gay men do not use condoms all of the time and each year there are thousands of new infections. PrEP has the potential to prevent new infections among some of the men who are most at risk of acquiring HIV.

Condom use is not the only strategy that gay men employ to prevent transmission of HIV. For example, gay men have selected partners on the basis of HIV status, made agreements in their relationships, withdrawn before ejaculation or chosen to only be a top in unprotected sex as ways to reduce their HIV risk. None of these methods, including condom use 4, is 100% safe.

PrEP is not a replacement for condom use. Instead it is an additional method of preventing HIV transmission, to be added to the other strategies that gay men already use.

How effective is PrEP?

Data from trials of PrEP suggest that it is very effective at preventing HIV, similar to condom use, as long as treatment is taken daily.5 PrEP does not prevent the transmission of other sexually transmitted infections.

Why take HIV treatment to avoid taking HIV treatment?

If you do get HIV, you’ll have to take lifelong treatment. PrEP consists of fewer drugs and need only be taken during periods you are at risk of HIV. Most gay men will find that their sexual behaviour changes over time. If, for example, someone has lots of sexual partners when they are between boyfriends, PrEP might be appropriate at this time. If they can avoid getting HIV when they are taking risks then they will not have to keep on taking HIV medication when they are not taking risks.

Will PrEP encourage risky behaviour?

We don’t know yet. We need to know exactly what impact taking PrEP has on gay men’s risk, as well as gather more data about how easy it is for gay men to stick to taking daily medication. For these reasons there is a study, called the PROUD study, which is recruiting gay men who may be at risk of getting HIV , to find out what impact PrEP has on sexual behaviour and how well gay men are able to use it. The PROUD study will give us important information on the role which PrEP may play in HIV prevention.

September 2013

For further information on the PROUD study:

For further information on PrEP:


1 Grant RM et al, for the iPrEx study team. Preexposure Chemoprophylaxis for HIV Prevention in Men Who Have Sex with Men. NEJM 363:2587-2599. 2010.

2 Health Protection Agency. HIV in the United Kingdom: 2012 Report . London: Health Protection Services,Colindale. November 2012.

3 Phillips AN et al. Increased HIV Incidence in Men Who Have Sex with Men Despite High Levels of ART-Induced Viral Suppression: Analysis of an Extensively Documented Epidemic . PLoS ONE 8(2): e55312. doi:10.1371/journal.pone.0055312.

4 Smith D et al. Condom efficacy by consistency of use among MSM: US. 20th Conference on Retroviruses and Opportunistic Infections, Atlanta, abstract 32, 2013. See this report.

5 Anderson P et al. Intracellular tenofovir-DP concentrations associated with PrEP efficacy in MSM from iPrEx . 19thConference on Retroviruses and Opportunistic Infections, Seattle, abstract 31LB, 2012.

prep partners