OBJECTIVES:To determine the non-inferiority of placebo Individualised Western Herbal Medicine (IWHM) tinctures compared with true IWHM tinctures. DESIGN:Randomised double blind comparability study. SETTING:Pharmacy department of an NHS integrated medicine hospital. INTERVENTIONS:The IWHM intervention consisted of mixed tinctures of five herbs from a list of eleven herbs for which chronic knee pain is an established indication. Placebo IWHM tinctures contained food and colouring extracts, designed to mimic as closely as possible the taste, smell and appearance of true IWHM. MAIN OUTCOME MEASURES:The primary outcome of the study was the proportion of patients who indicated that they believed they were taking true IWHM. Secondary outcomes included the palatability of the true and placebo tinctures. RESULTS:64% of the placebo group indicated that they believed they had consumed true IWHM, compared with 60% of the true IWHM group. The palatability of the placebo IWHM was also acceptable to participants, and similar to the palatability of true IWHM. CONCLUSIONS:The findings from the present study indicate that the placebo tinctures were non-inferior to the true IWHM tinctures in terms of participants' ability to correctly identify them as herbal tinctures by their taste, smell and appearance. The placebo tinctures could be utilised in future double blind, placebo controlled randomised trials of IWHM.