A study analyzing data on 78,560 people at 29 Australian clinics reportedly found that, after DoxyPEP recommendations were introduced, syphilis and chlamydia diagnoses were respectively 55% and 36% below predictions based on prior trends. DoxyPEP is a prevention strategy in which certain high-risk groups take doxycycline within 72 hours after sex. Because individuals were not randomly assigned, the entire decline cannot be attributed to the drug, and gonorrhea showed no significant change. Antibiotic resistance and the need for regular testing remain concerns. Eligibility should be discussed in clinical care; taking antibiotics on one’s own is not a substitute.