Recent studies have provided evidence for the effectiveness of using doxycycline (Doxy-PEP) to prevent bacterial sexually transmissible infections (STI), namely chlamydia, gonorrhoea, and syphilis, among gay, bisexual, and other men who have sex with men who have experienced multiple STIs. However, there remain several unanswered questions around potential adverse outcomes from Doxy-PEP, including the possibility of inducing antimicrobial resistance in STIs and other organisms, and the possibility of disrupting the microbiome of people who choose to use Doxy-PEP. This interim position statement from the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine aims to outline the current evidence for Doxy-PEP, and to highlight potential adverse outcomes, to enable clinicians to conduct evidence-based conversations with patients in Australia and Aotearoa New Zealand who intend to use Doxy-PEP.