About
The DoxyPEP study is now closed to enrollment. If you are a current or former study participant, please reach out to the study team for more information.
The Doxy PEP study was organized as a response to the high rates of syphilis, gonorrhea and chlamydia among men who have sex with men and transgender women in the US.
DoxyPEP campaign poster
Preliminary findings from a French study done in 2017 suggests that doxycycline taken 24-72 hours after condomless sex (as post-exposure prophylaxis or PEP), reduced new cases of syphilis and chlamydia by 70% but had no effect on reducing gonorrhea. Over half of gonorrhea is resistance to doxycycline in France, and about one quarter of gonorrhea in the US is as well.
In order to guide policy about doxycycline PEP for STI prevention, we need more information about doxycycline PEP’s effectiveness, safety and effect on antimicrobial resistance in both men who have sex with men (MSM) and transgender women (TGW) living with HIV, in addition to MSM and TGW on PrEP.
We designed the doxyPEP study to learn whether doxycycline PEP reduces syphilis, chlamydia and gonorrhea among MSM and TGW on PrEP and those living with HIV. We also are studying the effect on antimicrobial resistance, specifically whether intermittent use of doxycycline as PEP leads to resistance in gonorrhea, chlamydia and syphilis, Staph Aureus and other bacteria that we commonly carry.