A new study confirms that taking doxycycline after sex can dramatically lower the risk of certain sexually transmitted infections. Published in JAMA Internal Medicine, the research shows that doxyPEP—short for doxycycline post-exposure prophylaxis—reduced chlamydia risk by 79%, syphilis by 80%, and gonorrhea by 12%. The study focused on Kaiser Permanente Northern California, where doxyPEP was offered to gay and bisexual men starting in 2022. Around 12,000 people from this focused group were treated for HIV, and among them over 2,250 received doxyPEP in its first year. STI rates dropped significantly in this group, while those who didn’t take doxyPEP saw no change. However, according to Michael Traeger of Harvard Pilgrim Health Care Institute “Interventions that are effective in clinical trials don’t always end up working in real-world settings.” Though researchers note concerns about antibiotic resistance, senior researcher Julia Marcus emphasizes doxyPEP’s potential benefits for reducing STI transmission and improving sexual health.
