PrEP

PrEP (Pre Exposure Prophylaxis) is medication that you can take to stop yourself from getting HIV. You can take it either every day or before and after sex. If you take it correctly, it is extremely effective at stopping HIV infection.

PrEP is a medication that you can take to prevent HIV infection. It contains drugs that are commonly used to treat HIV- emtricitabine (FTC) and tenofovir DF (TDF). 

Taking PrEP before having sex means that it blocks HIV if it gets into your body, stopping it from infecting you. 


If you are at risk of being exposed to HIV, you should consider taking PrEP. It could also be appropriate for you if condoms are not always used. 

For example:

  • Gay, bisexual and other men who have sex with men.
  • People in communities with high rates of HIV (e.g. many African communities).
  • People in a relationship with a person living with HIV who is not on successful treatment.
  • Trans people, especially if they are having sex with gay, bisexual and other men who have sex with men. 
  • If you use some recreational drugs- especially Chemsex (meth, meph or GHB). 

PrEP can be taken in two different ways:

  • One tablet per day.
  • "Event based PrEP" taken only when needed, as follows:
    1. Two tablets between 2 and 24 hours before sex.
    2. One tablet after sex (24 hours after the first dose). 
    3. One tablet 48 hours after the first dose. 

If you are struggling to remember to take your PrEP, it's best to pick a time that is convenient for you and stick to a routine. You could keep a diary and mark off each day, or set an alarm on your phone. You could also use a pill box because this is a simple way to way to know if you have missed your meds. 

Rough timing is okay. A late "pre" dose provides some protection. For anal sex, four doses every week provides more than 95% protection. 

If you are taking PrEP daily, you will still have very high protection if you miss the odd dose. 

Note that daily PrEP is the only option for women and trans people who want protection from vaginal sex, or people who have Hepatitis B. 


PrEP is now available for free from certain sexual health clinics as part of the IMPACT trial in England. You can find out if your local clinic is taking part in the trial at the moment by clicking here. Remember to keep checking back on this website to see if there has been any changes to clinics offering PrEP. It's also got plenty of other useful information about the IMPACT trial. 

Some people are also ordering generic versions of PrEP online. You can find out more information by clicking here. This resource includes information on where to buy PrEP online from trusted sites (online suppliers where drug testing has confirmed that the meds are genuine)

Generic PrEP costs around £40 for 30 tablets (one month's supply for daily dosing but longer for event-based dosing). Generics contain the same active ingredients as branded meds, but cost 90% less (examples of generics include Ricovir-EM by Mylan and Tenvir-EM by Cipla). Just make sure that they contain both TDF and FTC. 

If you are considering buying PrEP online, you will still need to talk to your sexual health clinic. They will give you advise on how to safely take PrEP. They will also help you to get the tests that you need, such as for HIV and kidney function checks. 


  • An HIV test. PrEP is only for HIV negative people so you'll need to confirm this before you start taking PrEP. 
  • STI tests, including Hep B. It's good practise to regularly check for other STIs. This needs to include Hep B because PrEP meds suppress Hep B.
  • Kidney tests. Routine kidney monitoring, from blood or urine is needed to check that your kidney function isn't being affected by PrEP.

PrEP will not protect you from other STIs (such as Chlamydia, Gonorrhoea and Syphilis) or an unplanned pregnancy. If you are on PrEP, regular STI testing is recommended. 

You can also use condoms in addition to PrEP to protect yourself from other STIs and unplanned pregnancy. Pregnancy can also be prevented by a range of other methods of contraception


PrEP is extremely effective at preventing HIV infection if it is taken correctly. This has been shown in major PrEP studies. 

If taken incorrectly, PrEP may not work.


The drugs used in PrEP are the same as those used in HIV medications, taken my thousands of people living with HIV. They have no serious side effects and are very safe. 

If you get mild side effects, they can occur for the first week or so, but then they usually stop. 

You might experience nausea, headaches and tiredness. In very rare cases, PrEP might affect kidney function. This is why it is important to go for kidney function tests as recommended. 

If you forget to take your PrEP and become HIV positive, there is a small risk of resistance to HIV medication. However, this was very rare in the PrEP studies. 


Additional resources

Prepster

More information on PrEP and the IMPACT trial
Find out more

Buying PrEP online

A leaflet on getting PrEP online and accessing health checks from the NHS
Find out more

The PROUD study, a PrEP clinical study in the UK

For more information, click here
Find out more