English | Español

STI PEP

STIs are preventable through barrier protection like condoms during sex, or a new method — doxyPEP. Sexually transmitted infection post-exposure prophylaxis (STI PEP) or doxycycline post-exposure prophylaxis (doxyPEP) is the use of doxycycline to prevent people from acquiring bacterial STI (syphilis, gonorrhea, or chlamydia).

  • DoxyPEP is the “morning after pill” for STI prevention.
  • It does not prevent HIV, mpox, herpes, HPV, or other STIs.

  • DoxyPEP is an antibiotic that stops bacteria before they can develop a full infection. It lowers the chances of a STI by about two-thirds. DoxyPEP is for people who do not use condoms consistently.
  • DoxyPEP should be taken within 24 hours (and up to 72 hours) after condomless sexual contact (oral, genital, or anal).
  • DoxyPEP can be taken every 24 hours, for continued exposure.

  • 74-89% effective for preventing chlamydia
  • 77-87% effective for preventing syphilis
  • 51-57% effective for preventing gonorrhea

*DoxyPEP was studied among gay/bisexual men and transgender women either with HIV or on PrEP.

  • If you are a man or transgender woman who has sex with men, doxyPEP may be a tool you can use to avoid STIs. This medication, when taken after unprotected sex, helps prevent against bacterial STIs like syphilis, gonorrhea, and chlamydia.

  • DoxyPEP has only been found effective in men who have sex with men and transgender women, but clinicals studies in other groups are ongoing. Talk with your health care provider about your risk for STIs. Some providers prescribe doxyPEP to many different people.

  • DoxyPEP is a prescribed medication.
  • You need to test negative for STIs at body sites where you have sexual contact before getting a doxyPEP prescription.
  • Your regular health care provider, specialty LGBTQ+ health care providers, HIV or PrEP care providers, and some other specialists often offer DoxyPEP. DPH health departments also offer DoxyPEP.

  • DoxyPEP only works against bacterial STIs.
  • HIV PrEP prevents HIV infection and can be taken with doxycycline.
  • Mpox and HPV (genital warts) can be prevented through vaccination. There are vaccines against hepatitis A and B that are also recommended.
  • Condoms are effective at protecting against STIs when used correctly and consistently.

  • Take two capsules within 24 hours of unprotected sex. Don’t take more than one dose in a 24-hour period.
  • Doxycycline should be taken with a full glass of water to prevent stomach irritation.
  • Swallow the capsules whole. Do not open or crush the capsules.
  • If doxycycline upsets your stomach, you may take it with food.
  • Do not take more than 200 mg every 24 hours.

To find a clinic near you, please visit the Public Health Clinics page or call (855) 472-3432.

DoxyPEP Overview

The potential benefits and risks of fighting STIs with doxycycline