Australian clinic data suggest it may: after national guidance, syphilis diagnoses fell 1.3% monthly and chlamydia diagnoses fell 2.3% monthly. The report examined men attending a network of Australian health services. Researchers tracked monthly diagnoses from January 2022 through December 2025. They compared trends before and after national guidance released in October 2023. Doxycycline PEP means taking the antibiotic doxycycline after sex to help prevent some bacterial infections. Before guidance, syphilis diagnoses had been rising by 1.8% each month. Afterwards, they fell by 1.3% each month. Chlamydia diagnoses went from a stable trend to a 2.3% monthly decline. These were changes over time, not sudden drops when guidance appeared. Prescription records also suggested growing use. A separate check covered 15,719 men at 16 clinics. Of those men, 4,001 received at least one prescription with instructions suggesting use after sex. Those prescriptions made up 0.04% of all doxycycline prescriptions before guidance. That share rose to 27.7% after guidance. The share of tests coming back positive also fell for both infections. That supports a real decline, rather than simply fewer tests being done. Still, testing habits may have changed too. These clinic-wide trends do not prove cause and effect. They also do not show how much any one person's risk changed. For BioSocial members, the useful takeaway is to track context alongside results. Test dates, results, and records of use can make personal timelines clearer. Comparing notes with the community may help reveal differences in testing habits, without treating one person's experience as proof. What have you noticed in your test results or testing routine over time?