Ethical challenges of placebo use in herbal medicine trials: multiple stakeholder perspectives from qualitative interviews

Abstract Background The ethical use of placebos in herbal medicine (HM) clinical trials remains contested, particularly in contexts where traditional medical systems shape patients’ beliefs and expectations. Complexities in placebo preparation, insufficient transparency, and inconsistent consent practices pose challenges not only to scientific validity but also to ethical standards. This study aimed to explore stakeholder perspectives on placebo use in HM trials, with a specific focus on ethical concerns related to trust, informed consent, and trial integrity. Methods In-depth qualitative interviews were conducted with 23 stakeholders, including clinical investigators, research coordinators, trial managers, pharmaceutical staff, and patient representatives. We applied an inductive, framework-based thematic analysis to identify key perceptions, challenges, and needs regarding placebo use. Results Participants demonstrated diverse understandings and attitudes toward placebos. Medical professionals, who often had higher levels of formal medical training, tended to describe placebos from a scientific perspective, whereas patients more commonly expressed skepticism rooted in concerns about trust and transparency. Pharmacists reported substantial challenges in developing indistinguishable HM placebos, raising questions about the ethical implications of adding small amounts of active ingredients. Participants also highlighted inconsistent practices in placebo composition and similarity evaluation, which raised concerns about blinding integrity and transparency, as well as insufficient communication that affected participant trust and overall trial integrity. Conclusions Differences in professional and educational background appeared to shape how stakeholders perceived HM placebos, influencing informed consent and ethical conduct in trials. Enhancing understanding and transparency in placebo composition and similarity evaluation is essential to uphold ethical and scientific integrity of HM trials and to guide the development of clear guidelines for HM placebo design and communication. Clinical trial number not applicable.