53 outpatients suffering from common cold (flu) were randomly assigned to either a therapy with acetylsalicylic acid (ASA) or the homeopathic drug Eupatorium perfoliatum D2 in a controlled clinical trial. The efficacy of the drugs was assessed on day 1, 4 and 10 of the infection by symptom check lists and physical examinations. Neither subjective complaints nor body temperature or laboratory findings showed any significant differences between groups which was taken as evidence that both drugs were equally effective.