Schmidt F. conducted volume testing of 14 preparations on 1975 smokers by means of a double-blind placebo-controlled experiment. Tabex was given to 181 patients. The results obtained show that patients treated with Tabex have had optimum improvement. 103 patients (157%) gave up smoking, after 3 months this percentage decreased to 38%. Tabex is followed by the drugs niperli (54% and 48% respectively), atabaco (54% and 29% respectively), citotal (50% and 36% respectively), unilobin, potassium chloride, potassium granulate, potassium citrate, nicobrevin, targophagin, etc. The volunteers received by mail instructions concerning the mode of treatment, thus avoiding the influence of the extrapharmacological factors, hence the results registered by the patients themselves in inquiry forms are maximally reliable.