Doxycycline Post-Exposure Prophylaxis (Doxy-PEP) is a way to help reduce the risk of bacterial sexually transmitted infections (STIs). These STIs are gonorrhea, chlamydia, and syphilis. Doxycycline is a commonly-used antibiotic with a low risk of side effects. Doxy-PEP involves taking the medication after having condomless oral, anal or insertive vaginal sex, ideally within 24 hours but no later than 72 hours.
People born with a penis:
In people born with a penis (cis men, trans women and non-binary people), studies have shown that Doxy-PEP reduces some but not all bacterial STIs. Research has found that Doxy-PEP has protective benefits in the urethra/penis, rectum and throat.
One study showed that in people taking HIV PrEP, Doxy-PEP reduced syphilis rates by approximately
87%, chlamydia by 88% and gonorrhea by 55%.
People born with a vagina:
Current research indicates that Doxy-PEP is not effective for people born with vaginas (cis women, trans men and non-binary people) who have receptive vaginal sex. If this applies to you but you think you may benefit from Doxy-PEP, talk to your clinician.
Doxy-PEP may be right for you if:
- You have had a bacterial STI and condomless anal or oral sex with people who were born with a penis in the past year.
- You have had syphilis before.
- You have had multiple partners who were born with a penis in the past year, even if you have not previously been diagnosed with an STI.
Doxy-PEP may not be right for you if:
- You have a known allergy to doxycycline or tetracycline medication.
- You have a known diagnosis of Myasthenia Gravis.
- You use certain medications like barbiturates, phenytoin, carbamazepine, isotretinoin, or others.
- You are pregnant or able to get pregnant.
- You are breast or chest feeding.