Doxy PEP or Doxycycline (Doxy) for post-exposure prophylaxis (PEP) is a way to prevent bacterial sexually transmitted infections (STIs) for those who are at risk.  Doxy PEP is simple—it means taking 200 mg Doxycycline within 72 hours after having condomless sex (but even better within 24 hours after having sex).

It works! In three large randomized controlled clinical trials, 200 mg of doxycycline taken within 72 hours after sex reduced syphilis and chlamydia infections by >70% and gonococcal infections by 50%.  Studies have shown that Doxy PEP works best for gay, bisexual and other men who have sex with men who have had a bacterial STI in the last year, or who have had condomless sex in the last year—however others may also benefit from this prevention strategy.  Having Doxy PEP on hand is a tool that you can use to prevent syphilis, gonorrhea and chlamydia.   Ask your provider about Doxy PEP.

For more information about Doxy PEP here are some important references.

CDC   https://www.cdc.gov/mmwr/volumes/73/rr/rr7302a1.htm
https://www.cdc.gov/mmwr/volumes/73/rr/pdfs/rr7302a1-H.pdf
CDPH https://www.cdph.ca.gov/Programs/CID/DCDC/CDPH%20Document%20Library/CDPH-Doxy-PEP-Recommendations-for-Prevention-of-STIs.pdf
ACPHD  https://acphd.org/health-alerts/advisory/information-to-healthcare-providers-on-doxy-pep-feb-07-2023/
UCSF  https://www.sfcityclinic.org/services/sti-and-hiv-prevention/doxy-pep
East Bay Getting to Zero (EBGTZ)  https://www.ebgtz.org/resource/doxy-pep/

This report describes a recommendation from CDC for clinicians to use doxy PEP to help reduce incidents of syphilis, chlamydia, and gonorrhea in populations at high risk for these infections.
CDC Clinical Guidelines on the Use of Doxycycline