Clinical trial, with positive findings, on 217 patients with bronchitis who were treated at doctors’ practices in Germany. Approximately half of the patients were randomly allocated to receive a combination homeopathic medicine called Bronchiselect, and the others received a dummy pill (placebo); they were not told which treatment group they were in. After 3 weeks of treatment, the patients receiving homeopathy had fewer days of coughing than the patients receiving placebo.
Diefenbach M, Schilken J, Steiner G, Becker HJ (1997). Homöopathische Therapie bei Erkrankungen der Atemwege. Auswertung einer klinischen Studie bei 258 Patienten [Homeopathic therapy in respiratory tract diseases. Evaluation of a clinical study in 258 patients]. Zeitschrift für Allgemeinmedizin; 73:308–314.