Post-exposure prophylaxis, PEP, and pre-exposure prophylaxis, PrEP, provide effective protection against HIV infection. Both treatment options are available to men and women. They are taken at different times relative to potential HIV exposure.

PEP is taken following potential exposure to HIV, whereas PrEP is taken before any exposure to the virus. PrEP is often taken by the partners of HIV positive people, particularly those for whom the viral load is still detectable. PEP and PrEP are not suitable treatments for those who are HIV positive.


  • PEP is a treatment taken following the potential exposure to HIV and helps to prevent the virus from taking hold in the body.
  • PEP is often used as an emergency medication for those who believe they may have caught HIV.
  • PEP treatment lasts for 28 days. It is important that you start the course of medication within 72 hours, ideally 24 hours, following any incident of concern.
  • PEP can only be prescribed by a doctor.
  • PEP is not effective against any other STIs.

PEP has an extremely high success rate and the sooner you start your treatment, the more likely it is to work. If you stop taking your course of PEP during the 28-day period, you may compromise how effective the treatment is for you.

Once you have finished your course of PEP, you should take an HIV test to be sure that you are free from infection. Your Better2Know testing options include:

You should also consider the Better2Know Platinum Screen, as if you have been exposed to HIV you may also have been at risk of other STIs.

Please visit the Terrence Higgins Trust website to discover more about PEP treatment.


  • PrEP is a course of tablets taken before sex to help stop people from getting HIV.
  • PrEP has been found to be effective in both regular and on demand doses - your doctor will be able to advise you on this.
  • PrEP is available on the NHS in both Wales and Scotland. It is currently being trialled in England. You can also get a private prescription.
  • If you are HIV negative and take your PrEP medication as instructed, you will not require PEP treatment as well.
  • PrEP will not protect you against any other STIs.

If you are using PrEP it is advisable to get a Full Screen once every three months, so you can get tested for any other infections.

You can find out more about PrEP treatment by clicking here.

HIV in the UK

HIV remains a serious health concern in the United Kingdom. There are around 6,000 new diagnoses every year, with groups such as black Africans and men who sleep with men (MSM) amongst the most likely to be affected. According to the global HIV charity AVERT, over 10,000 people living with HIV in the UK are believed to be unaware of their status. This means that their infection has not been treated and are therefore at high risk of passing the virus on.

Booking Your Test

If you have taken PEP or PrEP and require a confirmatory test or have any other concerns about HIV, please contact Better2Know to arrange a confidential appointment at a private clinic near you. Call our dedicated team today on the telephone number provided, or book online using the orange button above.