DoxyPEP involves taking doxycycline, an antibiotic, as a ‘Post-Exposure Prophylaxis’ for bacterial STIs after having sex without a condom. The idea is that taking doxycycline soon enough after unprotected sex will kill any STI-causing bacteria before it has the chance to cause a full-blown infection.
While not as well studied as PrEP for HIV (Pre-Exposure Prophylaxis), preliminary findings have shown that taking DoxyPEP after sex could reduce the risk of STIs such as gonorrhoea, chlamydia and syphilis by up to 70%.
Doxycycline is currently widely used as a first-line treatment of choice for chlamydia, and in some cases syphilis and gonorrhea.