Doxycycline Post-Exposure Prophylaxis (DoxyPEP) is a way to help reduce the risk of bacterial sexually transmitted infections (STIs). These STIs are highly effective against chlamydia and syphilis. Doxycycline is a commonly-used antibiotic with a low risk of side effects. DoxyPEP 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 DoxyPEP reduces some but not all bacterial STIs. Research has found that DoxyPEP has protective benefits in the urethra/penis, rectum and throat.
One study showed that in people taking HIV PrEP, DoxyPEP reduced syphilis rates by approximately
80%, and chlamydia by 79%.
People born with a vagina:
Current research indicates that DoxyPEP 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 DoxyPEP, talk to your clinician.
DoxyPEP 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.
DoxyPEP 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.
To learn more about DoxyPEP, check out our guide to DoxyPEP here.