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.

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

PrEP is effective for all genders, it is also safe when taking gender-affirming hormones.

PrEP is safe when taking HRT for the menopause. PrEP is safe to use with all hormonal contraception (ring, patch, the pill or an implant).

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 any tablets. 

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. 

For more info on dosing, click here.

PrEP is now available for free on the NHS through your local sexual health clinics to anyone, regardless of your immigration status. There may be a slight waiting list, and the easiest way to get on that list is to call your local clinic and ask to speak to someone about PrEP. They will take your details and a consultant will call you back to discuss how appropriate PrEP is for you. 

If you'd like help accessing PrEP, contact your local MESMAC office

  • A 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 as prescribed. This has been shown in major PrEP studies.

The drugs used in PrEP are the same as those used in HIV medications, taken by millions of people worldwide 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. 

PrEP is safe to take while pregnant and it does not stop you getting pregnant. If you do get pregnant, tell your doctor as soon as possible. If you are still at risk of HIV, continue PrEP until you have spoken to your doctor.

If your doctor or health visitor says your baby is healthy, you can take PrEP daily if you are breastfeeding. PrEP passes into breast milk in very small amounts and it is unlikely to cause any side effects in your baby.

Additional resources


FAQs about PrEP
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