What is PrEP?

PrEP stands for pre-exposure prophylaxis.

• HIV PrEP is taken before sex, so it is pre-exposure. But it also needs to be taken afterwards too. Prophylaxis means to prevent infection.
• Last year, more than 100,000 people in the UK started or continued oral PrEP.

Oral PrEP usually contains two HIV drugs in a single pill. This is usually TD (tenofovir disoproxil) plus FTC.

A version using TAF (tenofovir alafenamide) instead of TD is used by the NHS if you have kidney or bone issues. Generic TAF/FTC can also be bought cheaply online.

PrEP using a 2-monthly injection of cabotegravir is also being assessed for approval in the UK.

Studies are also ongoing using a 6-monthly injection of lenacapavir. This includes the PURPOSE 5 study in the UK and France. [1]

PEP and doxyPEP

PrEP is different to HIV PEP. [2]

PEP involves taking one month of HIV drugs AFTER unprotected sex to reduce the chance of HIV. HIV PEP can only be used by people who are HIV negative.

doxyPEP involves taking a single dose of the antibiotic doxycycline after sex to reduce the chance of syphilis and chlamydia. New guidelines on doxyPEP in the UK were published in June 2025. [3]

DoxyPEP can be used by anyone at risk of these STIs. This includes people who are HIV positive or HIV negative.

From August 2025, a vaccine to prevent gonorrhoea will also be available in the UK.

References

1. Gilead Purpose 5 study.
   www.purposestudies.com/purpose5
2. i-Base. All you need to know about HIV PEP.
   i-base.info/qa/factsheets/pep-faq
3. i-Base. UK guidelines on doxyPEP to prevent syphilis. (June 2025)
   i-base.info/htb/51304
4. UKHSA. A guide to the Meningococcal B vaccine for protection against Gonorrhoea. (June 2025)
   www.gov.uk/government/publications/meningococcal-b-menb-vaccination-against-gonorrhoea-guide/a-guide-to-the-meningococcal-b-vaccine-for-protection-against-gonorrhoea

Last updated: 1 July 2025.