As a general rule, any clinical study where the result is already known or when the investigator(s) compares an assigned treatment against another assigned treatment known to be ineffective in the study population (e.g., in a population with known clarithromycin resistance) is unethical. As susceptibility-based therapy will always be superior to empiric therapy in any population with a prevalence of antimicrobial resistance >0%, any trial that randomizes susceptibility-based therapy with empiric therapy would be unethical. The journal Helicobacter welcomes susceptibility or culture-guided studies, studies of new therapies, and studies of adjuvants and probiotics. However, the journal will not accept for review any study we judge to be lacking clinical equipoise or which assign subjects to a treatment known to be ineffective, such as a susceptibility-based clinical trial with an empiric therapy comparator. To assist authors, we provide examples and suggestions regarding trial design for comparative studies, for susceptibility-based studies, and for studies testing adjuvants or probiotics.