Post-Exposure Prophylaxis All what you need to know about PEP?

what is pep uk

What is it?

PEP (Post-Exposure Prophylaxis) is HIV medication (called Truvada) that you may be able to take if you have been exposed to HIV or believe you have. This medication is a course that lasts for 28 days and it may be able to prevent you from becoming infected with HIV as long as you begin the treatment within 72 hours of putting yourself at risk. This is most commonly taken after having unprotected sex or if you have a condom break during sex. It is not 100% effective, but it can offer some protection from the virus.

how do I get prophylaxis

How do I get PEP?

You can only start a course of PEP by getting the drug on prescription. You can do this by attending a sexual health or GUM clinic. You can also get the medication at Accident and Emergency (A&E) departments of hospitals, although some people do report it is harder to get the drug outside of large towns and cities. The medication is expensive, so clinics or hospitals will only give it to you if they believe you are genuinely at risk. You will always be tested for HIV before the medication is prescribed.

Standard PEP - a standard course of PEP need to be taken for 28 days as the following below:

  • days 1-5 - Truvada® (combined tablet: Tenofovir 300mg and Emtricitabine 200mg) one tablet once a day.
  • days 1-5 - Kaletra® (combined tablet: Lopinavir 200mg and Ritonavir 50mg) two tablets twice a day (with or without food).

In addition an anti-emetic and an anti-diarrhoeal agent is routinely prescribed:

  • Domperidone (10mg tablet)- one tablet three times a day (when needed for nausea or vomiting).
  • Loperamide (2mg tablet) - two tablets at the first sign of diarrhoea or loose bowel motion then one tablet when needed thereafter. Maximum of eight tablets in 24 hrs.
  • Days 6-28 - Truvada® (combined tablet: Tenofovir 300mg and Emtricitabine 200mg) one tablet once a day.
  • Days 6-28 - Kaletra® (combined tablet: Lopinavir 200mg and Ritonavir 50mg) two tablets twice a day (with or without food).
post exposure prophylaxis


PEP is at its most useful and effective when it is used as soon as possible after you put yourself at risk. You should aim to get to a clinic or hospital within 24 hours of being as risk of contracting HIV. PEP becomes less effective the longer you wait and clinics or hospitals will not give out the drug to anyone who has waited longer than 72 hours to present as being at risk after having unprotected sexual contact.

information about pep uk

Side effects

As with many medications, there are possible side-effects that you may develop after taking PEP. These are usually short-term problems and are often insignificant when balanced against the risk of contracting HIV. More common side-effects reported by those taking PEP include nausea, fatigue, diarrhoea and headaches, but not everyone will develop these.



You must act quickly if you feel you are at risk and would benefit from PEP treatment. Do not wait all weekend to act and do try A&E if your local sexual health clinic is not open. Say clearly to the clinic or hospital staff that you have been exposed to HIV and want to use PEP. You will not be given PEP if you do not first have an HIV test. The hospital or clinic will do this for you. You will also have a test once the treatment is complete, to be sure it was successful.

You might find it difficult to get PEP treatment at the A&E. Hospital staff can give you wrong information about PEP and send you to sexual health/GUM clinic. Remember that hospital has a responsibility to ensure that staff in the A&E department are aware of, and have accepted their responsibility to provide cover for PEP where appropriate.

Last updated August 1, 2018