What is PrEP?

PrEP stands for pre-exposure prophylaxis; in short, prophylaxis means treatment given or action taken to prevent disease. PrEP is taken as a daily pill to protect you from contracting HIV by 99% if adhered to daily. PrEP is taken as a precautionary measure and has been shown to be one of the most effective ways to prevent HIV infection.

The pill, taken daily by the mouth, is called Truvada, a combination of two drugs (tenofovir and emtricitabine).

The pill has been endorsed by the World Health Organisation and is now already available in a number of countries such as France, Canada, and Israel. The NHS is yet to commission PrEP in the UK; however, you can still purchase PrEP in the UK from a number of reliable online suppliers.

Based on multiple worldwide studies, the protection rate against HIV varies from 86%, 90%, and 99%, depending on which trial is taken into account. What we learn from the trials is that to achieve a 99% protection rate, you must adhere to the pill every single day in order to receive maximum protection.

PrEP Facts

Like HIV and PEP, there is also so much to learn about PrEP, we have put together some facts based on frequently asked questions we have received.

  • PrEP stands for pre-exposure prophylaxis.
  • PrEP can reduce the risk of being infected with HIV by 99% if used daily.
  • PrEP is not the same as PEP; whereas Truvada is also used as part of a PEP course, PEP is designed to eradicate the virus post exposure within a 72 hour window, not pre exposure.
  • PrEP is much less effective when it is not taken consistently.
  • PrEP is not a vaccine for HIV. A vaccine is designed to protect you for several years and usually comes in the form of an injection. PrEP is a daily pill you take to significantly decrease the risk of contracting HIV.
  • PrEP will not protect you against other sexually transmitted diseases (gonorrhea, syphilis, chlamydia, hepatitis, etc.).
  • The high courts are due to give their final word on whether the NHS will commission PrEP in November 2016 regarding the NHS’s appeal to commission the pill to people who are deemed “high risk.”


Side Effects

Many who start PrEP have claimed that they have experienced little to no side effects and any potential short term side effects are allegedly not supposed to last any more than two weeks. These short term side effects include:

  • Nausea
  • Abdominal cramping
  • Vomiting
  • Dizziness
  • Fatigue

Long term side effects may include gradual kidney damage; however, most sexual health clinics will be happy to monitor your kidneys whilst you are taking TDF/FTC PrEP.

PrEP and the NHS

Unfortunately, pre-exposure prophylaxis has never been and is still not available to those deemed at risk on the NHS.
Earlier in 2016, the NHS were reconsidering commissioning PrEP to those deemed a high risk; however, they delayed their decision. A statement said: “In light of representations from stakeholder groups, NHS England agreed to reconsider the decision.”

This took place on 31 May 2016 at the Specialised Services Commissioning Committee.
“In summary, the Committee considered and accepted NHS England’s external legal advice that it does not have the legal power to commission PrEP.”

After the decision to not roll out PrEP to those at risk, the National AIDS Trust (NAT) took their decision to the high courts and were then overruled, deeming the NHS responsible for commissioning PrEP in the UK.
The NHS has announced that they have already appealed the high court’s decision and we are still waiting on a final announcement due in November 2016.

*UPDATE*  04/12/2016

It has now been announced that the NHS England will be rolling out PrEP (pre-exposure prophylaxis) to 10,000 people as part of a brand new trial due to start in Spring 2017.

It is said that the trial will not be used to determine how effective Truvada as a prevention method to reduce risks of HIV transmission but rather to determine an accurate criteria of which patients are deemed more high-risk and also to determine how long patients should stay on the drug. PrEP has proven to have its maximum potential against HIV if adhered to daily.

The criteria of who will be eligible for the trial will include those who have had an STI in the last three months but full details of the criteria are yet to be released according to BuzzFeed news.


Many PrEP trials have been conducted in various countries over the world with outstanding, mind blowing results. Many of the results have determined similar outcomes in terms of what the real protection rate is when adhered to PrEP on a daily basis. When PrEP is adhered to daily, it has been concluded that it can offer up to a 99% protection rate. Through several studies the figure has been varying around the 86% mark, but much of this is down to the fact that many participants were not adhering to PrEP and there was simply not enough TDF/FTC in their system to offer full protection.

In 2012, a UK based study called PROUD enrolled 545 participants from 13 sexual health centres around the UK. The participants included gay men who reported having unprotected anal sex within the last three months and were likely to do the same again in the future. The randomised study allowed participants to receive ongoing pre-exposure prophylaxis for a one year period.

The study found 1.3 new infections per 100 person-years in the group that was given PrEP immediately, and 8.9 per 100 person-years in those who were not yet on PrEP. The 86% protection rate was the highest reported from any other conducted PrEP trial.

Only three men in the immediate PrEP group were infected with HIV, compared to 20 in the group who did not receive PrEP immediately. The three men who were infected in the immediate PrEP group were unlikely to have actually been taking PrEP when they were infected – one was probably infected before he started PrEP, and the other two had not collected their prescription of PrEP for several months before being diagnosed.

There are several other studies around the world that offer similar results; please see below to read more:

iPrexStudyFor gay and bi men and transwomen who participated in PrEP clinical trials

  • Participants: 2,500
  • Reduction in HIV infection including those who were not adhering to medication for weeks at a time: 42%
  • Reduction in HIV infection with detectable levels but were not fully adhering: 92%
  • Reduction in infection with those adhering daily through further analysis: 99%


PartnersPrEPStudyFor heterosexual women and men who participated in PrEP clinical trials

  • Participants: 4,500
  • Reduction in HIV infections without detectable PrEP in their blood: 75%
  • Reduction in HIV infections with detectable PrEP in their blood: 90%


Botswana TDF2 StudyFor heterosexual women and men who participated in PrEP clinical trials

  • Participants: 1,200
  • Reduction in HIV infections: 62%
  • It is not known if further analysis was performed to determine if the reduction percentage is based on PrEP being detectable in their bloodstream


FemPrEPFor heterosexual women and men who participated in PrEP clinical trials

  • Participants: 2,100
  • The trial was cut short as the majority of participants were not adhering as they should be based on the drug levels found in their blood
  • No accurate results were presented at the end of the trial