UK guidelines on doxyPEP to prevent syphilis

17 June 2025. Related: Early access, Guidelines, Coinfections and complications.

Simon Collins, HIV i-Base

On 9 June 2025 the British Association for Sexual Health and HIV (BASHH) published the first UK guidelines on doxycycline post-exposure prophylaxis (doxyPEP). [1]

This document includes 16 recommendations and although the main indication is cisgender gay and bisexual men and transgender women, it can also include other people at increased risk of syphilis.

DoxyPEP studies first reported benefits in 2022 when the first US guidelines were produced in the regions where doxyPEP had been studied. [2]

This is because guideline recommendations are not just related to the study populations – usually gay and bisexual men and transgender women – but also to background rates of bacterial STIs and concerns over tetracycline drug resistance and potential impact on the microbiome. [2, 3, 4, 5, 6]

For example, the 2024 US CDC guidelines still have a wider indication for doxyPEP to cover syphilis, chlamydia, and gonorrhoea. [3]

Australian guidelines recommended doxyPEP to primarily to protect against syphilis but reductions in chlamydia and gonorrhoea in some people might be important. [4]

DoxyPEP dosing is a 200 mg dose  (given as 2 x 100 mg capsules) within 24 hours of sex and no later than 72 hours. Anyone having potential risks over several days can take the 200 mg dose at the end of a 72 hour period. 

The BASHH guidelines also include auditable outcome measures and questions to prioritise in future research.

comments

These 46-page guidelines include a comprehensive review of current evidence and include wider stakeholder comments to make new recommendations for use across the UK. They are timely given the continued increase in syphilis cases recently reported in the UK STI data. [7]

The guidelines should hopefully broaden the number of people using doxyPEP under medical supervision, as over the last few years people in the UK have been buying doxycycline online, similar to the way early PrEP was used before it became available on the NHS.

Some of the debates about the indications for doxyPEP have limited practical implications because risks for the three main bacterial STIs are broadly similar and prophylaxis against one can’t be separated from potential impact on the others.

The EATG recently produced a useful factsheet on doxyPEP. [8]

References

1. BASHH. BASHH publishes UK-first guidelines on doxyPEP for the prevention of syphilis. (9 June 2025).
   www.bashh.org/news/1686/bashh_publishes_ukfirst_guidelines_on_doxypep_for_the_prevention_of_syphilis (press release)
   www.bashh.org/resources/141/doxycycline_postexposure_prophylaxis_2025 (download page)
   www.bashh.org/_userfiles/pages/files/guideline_doxypep_final_9thjune2025_v11.pdf (PDF)
2. San Francisco Department of Public Health. Doxycycline Post-Exposure Prophylaxis Reduces Incidence of Sexually Transmitted Infections. (21 October 2022).
   www.sfcityclinic.org/sites/default/files/2022-10/Health%20update_DoxyPEP_FINAL.1.pdf
3. US CDC. CDC Clinical Guidelines on the Use of Doxycycline Postexposure Prophylaxis for Bacterial Sexually Transmitted Infection Prevention United States 2024. Recommendations and Reports / June 6 2024 / 73(2)1–8
   www.cdc.gov/mmwr/volumes/73/rr/rr7302a1.htm
4. Australian Society for HIV Medicine (ASHM). Australian Consensus Statement on DoxyPEP. Australian consensus statement on doxycycline post‐exposure prophylaxis (doxy‐PEP) for the prevention of syphilis chlamydia and gonorrhoea among gay bisexual and other men who have sex with men. Med J Aust || doi: 10.5694/mja2.52258. (1 April 2024).
   https://www.mja.com.au/journal/2024/220/7/australian-consensus-statement-doxycycline-post-exposure-prophylaxis-doxy-pep
5. German STI Society (DSTIG). Position statement of the German STI Society on the prophylactic use of doxycycline to prevent STIs (Doxy-PEP, Doxy-PrEP). J Dtsch Dermatol Ges. 2024 Mar22(3):466-478. doi:10.1111/ddg.15282. Epub 2023 Dec 20.
6. IUSTI Europe Position Statement on use of DoxyPEP: June 2024
   iusti.org/wp-content/uploads/2024/06/DOXYPEP-Position-Statement-26_6_24-FINAL.pdf
7. UKHSA. UKHSA publishes latest STI data. (3 June 2025).
   www.gov.uk/government/news/ukhsa-publishes-latest-sti-data
8. EATG. New resources on DoxyPEP. (June 2025)
   https://www.eatg.org/publications/doxypep