Clinical trial, with positive findings, on 115 German army soldiers suffering from common cold. Approximately half of the soldiers were randomly allocated to receive a homeopathic medicine called Gripp-Heel and the others received Aspirin; they were not told which treatment group they were in. On the 4th and 10th days of treatment, there was no difference in symptom improvement between the two treatment groups, showing that Gripp-Heel and Aspirin were similarly effective.