What’s Behind The Major Drop In STI Cases? The Answer Might Surprise You
In recent years, syphilis has been on the rise, hitting record numbers across many communities. But for the first time in a while, there’s good news!
The use of doxycycline as a preventive antibiotic, known as doxyPEP, is showing promising results in reducing sexually transmitted infections (STIs), especially syphilis.

According to a report from the Centers for Disease Control and Prevention (CDC), the number of syphilis cases dropped by 10% from 2022 to 2023, with a 13% decrease among a key group that has historically been affected. This decline is bringing new hope to public health experts who have been fighting the STI battle for years.
So, how does it work? DoxyPEP involves taking a 200-milligram dose of doxycycline within 72 hours after condomless sex. This protocol has proven to reduce cases of syphilis and chlamydia by over 70% and gonorrhoea by about 50%, according to several studies. It’s a simple, accessible, and affordable option that fits into many people’s existing health routines, particularly those already using HIV prevention methods like PrEP.
The success of doxyPEP has already been seen in major cities like San Francisco, New York, and Chicago, where health departments have recommended it for certain groups. The CDC officially backed its use in June 2023, following the lead of local health authorities.
Why Now?
The rise of STIs in recent years has been linked to less condom use, especially since the introduction of effective HIV treatments. But the decline in syphilis cases shows that there is a shift happening. The increased use of doxyPEP is likely a key factor.
While this is a positive step, experts are still monitoring the long-term effects of widespread doxycycline use. There are ongoing studies to ensure that increased antibiotic use doesn’t contribute to drug resistance.
The next few years will be crucial in seeing how doxyPEP continues to impact public health. For now, though, it’s clear that this preventive measure is making a real difference. As more people hear about it and adopt it, we may continue to see the numbers drop.

