Randomized double-blind placebo-controlled trial of homoeopathic 'proving' for Belladonna C30

Homoeopathic drug pictures are developed by recording the symptomatic effects of homoeopathic remedies given to healthy volunteers (a 'proving'). In a double-blind randomized controlled trial we tested the hypothesis that individuals using an infinitesimal dilution of Belladonna (thirtieth potency, C30) would record more true symptoms, on a questionnaire that contained both true and false Belladonna proving symptoms, than those receiving placebo. 60 volunteers entered the study and 47 completed data collection. We were unable to distinguish between Belladonna C30 and placebo using our primary outcome measure. For the secondary outcome measure we analysed the number of individuals who proved to the remedy according to our predefined criteria: 4 out of 19 proved in the Belladonna C30 group and 1 out of 27 in the placebo group (difference not statistically significant). This pilot study does not demonstrate a clear proving reaction for Belladonna C30 versus placebo, but indicates how the question might be further investigated.