CDC endorses doxycycline after unprotected sex to prevent STIs, particularly in high-risk populations.

The US CDC has endorsed taking the antibiotic doxycycline after unprotected sex as a method to prevent chlamydia, gonorrhea or syphilis infections. This marks the first new prevention tool against sexually transmitted infections in decades, as STD rates have been rising, particularly among gay and bisexual men. The CDC recommends the morning-after pill for individuals with a previous STD and high risk of re-infection.