Study Design

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 study is recruiting participants in San Francisco and Seattle. Participants will be enrolled in the study for 12 months, and seen for scheduled follow-up visits every 3 months. STI testing will be conducted during these five scheduled visits, and participants with a positive STI test will return for treatment and for swabs of the affected site for resistance testing.

This is a randomized trial, in which 2/3 of participants receive doxycycline to take as PEP and 1/3 do not receive doxycycline PEP. The study is open label, meaning participants know whether they are assigned to doxycycline or not. We ask people who are not assigned to doxycycline not to take this medication through other means, unless prescribed for a specific infection.