doxy-PEP for Bacterial STIs

doxycycline prescription bottle with pills spilling out

Doxycycline Post-Exposure Prophylaxis (doxy-PEP) for the Prevention of Bacterial Sexually Transmitted Infections (STIs)

From 2020-2021 in Chicago, the number of chlamydia (CT) cases increased by 9%, gonorrhea (GC) cases increased by 1%, and primary and secondary (P&S) syphilis cases among women increased by 20%. Given the high rates of these STIs in Chicago and across the country, the Chicago Department of Public Health (CDPH) would like to inform all health care providers and community partners of a new biomedical intervention to prevent bacterial STIs, doxycycline PEP (doxy-PEP). Emerging evidence from a study among men who have sex with men (MSM) and transgender women (TGW) has provided evidence that a single dose of doxy-PEP given within 24 to 72 hours of condomless oral, anal, or vaginal sex, significantly reduces risk of acquisition of CT, GC, and syphilis.

CDC doxy-PEP Recommendations

The Centers for Disease Control and Prevention (CDC) has published doxy-PEP recommendations. CDPH has developed a clinical protocol for the delivery of doxy-PEP and guidance on offering doxy-PEP on a case-by-case basis in accordance with CDC recommendations. CDPH recommends the following:

  1. Recommend doxy-PEP to cisgender men or TGW aged 18 years or older who have tested positive for CT, GC, or syphilis in the previous 12 months and report condomless anal or oral sexual contact with one or more cisgender men or TGW partner in the past 12 months. The efficacy of doxy-PEP among young cisgender women is inconclusive.
  2. Offer doxy-PEP using shared decision making to cisgender men and TGW who report having multiple cisgender male or TGW sex partners in the past 12 months, even if they have not been previously diagnosed with an STI.
  3. Provide preventative sexual health counseling and education for sexually active individuals including appropriate condom use, doxy-PEP, HIV pre-exposure prophylaxis (PrEP), non-occupational HIV post-exposure prophylaxis (nPEP), and vaccinations (e.g., Hepatitis A/B, HPV, and mpox).


As a part of CDPH’s doxy-PEP package, we are offering the following resources:

Please reach out to if you have any questions about this guidance.