J Psychosom Res. 1993 Dec; 37(8): 851-60.
Does a highly diluted homoeopathic drug act as a placebo in healthy volunteers? Experimental study of Belladonna 30C in double-blind crossover design--a pilot study.
University of Freiburg, Rehabilitation Psychology, F.R.G.
A basic tenet of homoeopathy is that remedies which do not contain active molecules can have effects on the healthy human organism, by virtue of the specific preparation process of stepwise dilution and succussion, called potentization. The claim that a so called high 'potency' of a homoepathic remedy, Belladonna C30, could produce effects different from placebo, was investigated in a pilot study. In a double-blind crossover trial, 4 weeks of Belladonna C30 were compared to 4 weeks of placebo in 47 healthy volunteers. Data were collected daily. The number and types of changes were recorded into a predefined category system. Single-case evaluation showed differences between the two experimental phases for 21 subjects. Group evaluation showed no clearcut differences. The claim that homoeopathic potencies can produce symptoms other than placebo in healthy subjects should be put to further scrutiny.